ESRI ArcGIS iPhone API – Class Breaks Renderer Sample

by James Richards June 04, 2010

Introduction

Here is a quick sample demonstrating the use of a Class Breaks Renderer in the ESRI ArcGIS iPhone API. The sample queries an ArcGIS Server Map Service for cities in California and renders them as graphics based on the population. Here’s a screenshot of the app running in the simulator.

ClassBreaks

Click here to download the source code from this article.

[more]

Discussion

If you’ve been programming with any of the ESRI Client APIs, then you’ll recognize the Class Breaks Renderer concept. For those who aren’t familiar, here’s a snippet from the Working with Symbols and Renderers section of the ArcGIS iPhone SDK Concepts documentation:

A class breaks renderer symbolizes each Graphic based on the value of some numeric attribute. Graphics with similar values for the attribute get the same Symbol. The "breaks" define the values at which the symbology changes.

Code Listings

ClassBreaksViewController.h

#import <UIKit/UIKit.h>
#import "AGSiPhone.h"

#define kTiledMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer"
#define kDynamicMapServiceURL @"http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/0"

@interface ClassBreaksViewController : UIViewController<AGSMapViewDelegate, AGSQueryTaskDelegate> {
    AGSMapView *mapView;
    AGSGraphicsLayer *cityGraphicsLayer;
    AGSQueryTask *cityQueryTask;
    
}

@property (nonatomic, retain) IBOutlet AGSMapView *mapView;
@property (nonatomic, retain) AGSGraphicsLayer *cityGraphicsLayer;
@property (nonatomic, retain) AGSQueryTask *cityQueryTask;

@end

ClassBreaksViewController.m

#import "ClassBreaksViewController.h"

@implementation ClassBreaksViewController

@synthesize mapView;
@synthesize cityGraphicsLayer;
@synthesize cityQueryTask;

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
    
    // Set map view delegate
    self.mapView.mapViewDelegate = self;
    
    // Create tile base map layer
    AGSTiledMapServiceLayer *tiledLayer = [[AGSTiledMapServiceLayer alloc] initWithURL:[NSURL URLWithString:kTiledMapServiceURL]];
    [self.mapView addMapLayer:tiledLayer withName:@"BaseLayer"];
    [tiledLayer release];
    
    // Create grpahics layer
    self.cityGraphicsLayer = [AGSGraphicsLayer graphicsLayer];
    
    // Create symbols for the three class breaks
    AGSSimpleMarkerSymbol *lowSymbol = [AGSSimpleMarkerSymbol simpleMarkerSymbol];
    lowSymbol.color = [UIColor colorWithRed:151.0/255.0 green:216.0/255.0 blue:255.0/255.0 alpha:0.8];
    lowSymbol.outline.width = 0;
    lowSymbol.size = 15;
    
    AGSSimpleMarkerSymbol *mediumSymbol = [AGSSimpleMarkerSymbol simpleMarkerSymbol];
    mediumSymbol.color = [UIColor colorWithRed:255.0/255.0 green:165.0/255.0 blue:83.0/255.0 alpha:0.8];
    mediumSymbol.outline.width = 0;
    mediumSymbol.size = 20;
    
    AGSSimpleMarkerSymbol *highSymbol = [AGSSimpleMarkerSymbol simpleMarkerSymbol];
    highSymbol.color = [UIColor colorWithRed:222.0/255.0 green:0.0 blue:0.0 alpha:0.8];
    highSymbol.outline.width = 0;
    highSymbol.size = 25;
    
    // Create a class breaks renderer with a default simple marker symbol and an attribute field
    AGSClassBreaksRenderer *cityRenderer = [AGSClassBreaksRenderer
                                            classBreaksRendererWithDefaultSymbol:lowSymbol 
                                                               forAttributeField:@"POP1990"];
    
    // Create three AGSClassBreak objects, one each for low, medium and high populations
    AGSClassBreak* lowClassBreak = [AGSClassBreak
                                    classBreakInfoWithSymbol:lowSymbol forMinValue:DBL_MIN
                                    maxValue:50000.0];
    
    AGSClassBreak* mediumClassBreak = [AGSClassBreak
                                       classBreakInfoWithSymbol:mediumSymbol forMinValue:50000.0
                                       maxValue:250000];
    
    AGSClassBreak* highClassBreak = [AGSClassBreak
                                     classBreakInfoWithSymbol:highSymbol forMinValue:250000.0
                                     maxValue:DBL_MAX];
    
    // Create an NSMutableArray, fill it with the class break objects,
    // and set it to the renderer’s classBreaks property
    cityRenderer.classBreaks = [NSMutableArray arrayWithObjects:
                                lowClassBreak, mediumClassBreak, highClassBreak, nil];
    
    // Add the renderer to the graphics layer
    self.cityGraphicsLayer.renderer = cityRenderer;
    
    // Add the graphics layer to the map view
    [self.mapView addMapLayer:self.cityGraphicsLayer withName:@"CityGraphicsLayer"];
}

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
    
    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    self.cityGraphicsLayer = nil;
    self.mapView = nil;
    [super viewDidUnload];
}

- (void)dealloc {
    [cityGraphicsLayer release];
    [mapView release];
    [super dealloc];
}

#pragma mark AGSMapViewDelegate

// Called when the map view is loaded (after the view is loaded) 
- (void)mapViewDidLoad:(AGSMapView *)mapView {
        
    // Set up query task for cities and perform query returning all attributes
    self.cityQueryTask = [AGSQueryTask queryTaskWithURL:[NSURL URLWithString:kDynamicMapServiceURL]];
    self.cityQueryTask.delegate = self;
    
    AGSQuery *cityQuery = [AGSQuery query];
    cityQuery.where = @"STATE_NAME = 'California'";
    cityQuery.outFields = [NSArray arrayWithObject:@"*"];
        
    [self.cityQueryTask executeWithQuery:cityQuery];
    
    // Create extent to be used as default
    AGSEnvelope *envelope = [AGSEnvelope envelopeWithXmin:-118.6
                                                     ymin:33.6
                                                     xmax:-118.1
                                                     ymax:34.2
                                         spatialReference:self.mapView.spatialReference];
    
    // Call method to set extent, pass in envelope
    [self.mapView performSelector:@selector(zoomToEnvelope:animated:) 
                       withObject:envelope
                       afterDelay:0.5];    
}    

#pragma mark AGSQueryTaskDelegate

// When query is executed ....
- (void)queryTask:(AGSQueryTask *)queryTask didExecuteWithFeatureSetResult:(AGSFeatureSet *)featureSet {
    // Iterate the returned features (graphics) and add them to the graphics layer
    for (AGSGraphic *graphic in featureSet.features) {
        [self.cityGraphicsLayer addGraphic:graphic];
    }
    [self.cityGraphicsLayer dataChanged];
    
    // Clean up query task memory
    self.cityQueryTask = nil;
}

// If there's an error with the query task give info to user
- (void)queryTask:(AGSQueryTask *)queryTask didFailWithError:(NSError *)error {
    // Clean up query task memory
    self.cityQueryTask = nil;

    // Display error message
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error"
                                                    message:[error localizedDescription]
                                                   delegate:nil
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
    [alert show];
    [alert release];
}

@end

Summary

In this post you learned how to use a Class Breaks Renderer in the ESRI ArcGIS iPhone API to display cities of varying population with different symbols.

Click here to download the source code from this article.

I hope you are finding these posts on the ESRI iPhone API to be helpful. If you have any suggestions, ideas or feedback, please leave them in the comments below.

Additional Resources

Tags: , , ,

ArcGIS Server | ESRI | iPhone | Mobile

ESRI ArcGIS iPhone API – Integration with Core Location

by James Richards May 14, 2010

Introduction

Last week I started to familiarize myself with the ESRI ArcGIS iPhone API public beta and I blogged about my First Impressions. This week I had a chance to play around with it some more and I decided to investigate working with location. I enhanced my sample application from last week to include a Location button, which when pressed zooms the map to the current location and displays a custom push pin graphic.

Screen1     Screen2

Click here to download the source code from this article.

There are two ways you can work with location while writing an app with ESRI’s iPhone API:

ESRI’s AGSGPS class provides a convenient wrapper around Core Location if you don’t want (or need) to delve into the details of the framework.

[more]

ESRI AGSGPS Class vs. Apple Core Location Framework

Here’s how the ESRI iPhone API documentation describes the AGSGPS class:

“This object controls how the map responds to GPS input. To make the map start responding to GPS input, call the start method. The map will automatically zoom to the first location specified by the GPS input. You can control the zoom level by specifying the zoomLevel property. If the autoPan property is enabled, the map will recenter everytime a new GPS location is received. To make the map stop responding to GPS input, call the stop method. By default, the map uses a round, blue symbol to display the current location. You can replace this symbol with an image icon of your choice. This image must be included in the application bundle, it must be named GpsDisplay.png and it must be 35x35 pixels in size.”

The class definitely simplifies working with Core Location, but the trade off is that you are somewhat limited in what you can do. For example, Core Location includes the CLLocationManagerDelegate protocol which is “used to receive location and heading updates” so you can respond to them in your code. I’d like to see something similar in the ESRI iPhone SDK to give us more flexibility to respond to location updates. With the ESRI iPhone SDK, you just turn on the GPS and let the map do it’s thing.

For my sample app, I decided to work with the Core Location framework for finer grained control over the user interaction.

Implementation Details

The first step I took was to rearrange the UI in Interface Builder to accommodate the new button. I decided to add a proper toolbar along the bottom and center the new button and existing segment control. This required adding Flexible Bar Button Items on each side of the toolbar, as shown:

Finding the proper icon for the Location button was a bit tricky. Interface Builder doesn’t give you a way to specify this particular system icon for your button. I had to follow Diallo’s advice from this Stack Overflow question to get the icon from the UI Kit and save it to disk. I temporarily added this code to the viewDidLoad event, and ran the application once to write the icon out to my document directory.

UIImage* img = [UIImage kitImageNamed:@"UIButtonBarLocate.png"];
// Get the location of the Documents directory NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) ; NSString *imagePath = [paths objectAtIndex:0] ; NSString *filename = @"Locate.png" ; NSString *filepath = [NSString stringWithFormat:@"%@/%@", imagePath, filename] ; // Save the image NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(img)]; [imageData writeToFile:filepath atomically:YES];

If your not sure where the file gets saved, you can add an NSLog call to output imagePath to the Console. After the icon was saved, I removed the temporary code and copied the icon into the project directory, under the Resources group.

Once I had the view setup properly in interface builder, I modified the view controller’s header file to:

  • Import Core Location
  • Conform to the CLLocationManagerDelegate protocol
  • Declare members and properties for the location manager and locate button
  • Declare an IBAction method to run when the user clicks the locate button

I also cleaned up the previous week’s code a bit, to remove unnecessary AGSTiledMapServiceLayer members and properties.

Here is the new version of MyFirstMapAppViewController.h:

#import <UIKit/UIKit.h>
#import <CoreLocation/CoreLocation.h>
#import "AGSiPhone.h"

#define kTiledStreetMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"
#define kTiledImageryMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer"
#define kTiledReliefMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_ShadedRelief_World_2D/MapServer"

@interface MyFirstMapAppViewController : UIViewController<AGSMapViewDelegate, CLLocationManagerDelegate> {
    AGSMapView *mapView;
    CLLocationManager *locationManager;
    
    UIView *streetView;    
    UIView *imageryView;    
    UIView *reliefView;
    
    UIBarButtonItem *locateButton;
}

@property (nonatomic, retain) IBOutlet AGSMapView *mapView;
@property (nonatomic, retain) CLLocationManager *locationManager;

@property (nonatomic, retain) UIView *streetView;
@property (nonatomic, retain) UIView *imageryView;
@property (nonatomic, retain) UIView *reliefView;

@property (nonatomic, retain) IBOutlet UIBarButtonItem *locateButton;

- (IBAction)toggleLayer:(id)sender;
- (IBAction)showLocation:(id)sender;

@end

For the implementation file, Core Location is used in the following manner:

  • The location manager is created and started in viewWillAppear
  • The locate button is disabled in viewWillAppear to ensure that the button can’t be used until Core Location services have become available
  • A new graphics layer is created and added to the map in viewDidLoad
  • The location button is enabled in the location manager’s didUpdateToLocation event once core location is started and ready to use
  • When the user touches the Locate button, the showLocation method gets the location, creates and zooms to an envelope around that location, and displays a push pin graphic in the graphics layer
  • The location manager is shut down in viewWillDisappear

This code follows the same basic pattern shown in one of the examples in Head First iPhone Development.

Here is the MyFirstMapAppViewController.m file:

#import "MyFirstMapAppViewController.h"

@implementation MyFirstMapAppViewController

@synthesize mapView;
@synthesize streetView;
@synthesize imageryView;
@synthesize reliefView;
@synthesize locationManager;
@synthesize locateButton;

- (void)viewWillAppear:(BOOL)animated {
    // Setup location manager
    NSLog(@"Starting core location");
    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
    self.locationManager.delegate = self;
    [self.locationManager startUpdatingLocation];
    self.locateButton.enabled = NO;
}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.mapView.mapViewDelegate = self;
    
    AGSTiledMapServiceLayer *streetLayer = [[AGSTiledMapServiceLayer alloc] 
                                            initWithURL:[NSURL URLWithString:kTiledStreetMapServiceURL]];
    self.streetView = [self.mapView addMapLayer:streetLayer withName:@"Street"];
    [streetLayer release];
    
    AGSTiledMapServiceLayer *imageryLayer = [[AGSTiledMapServiceLayer alloc] 
                                             initWithURL:[NSURL URLWithString:kTiledImageryMapServiceURL]];
    self.imageryView = [self.mapView addMapLayer:imageryLayer withName:@"Imagery"];
    [imageryLayer release];
    
    AGSTiledMapServiceLayer *reliefLayer = [[AGSTiledMapServiceLayer alloc] 
                                            initWithURL:[NSURL URLWithString:kTiledReliefMapServiceURL]];
    self.reliefView = [self.mapView addMapLayer:reliefLayer withName:@"Relief"];
    [reliefLayer release];

    self.streetView.hidden = NO;
    self.imageryView.hidden = YES;
    self.reliefView.hidden = YES;

    // Create a graphics layer to display the push pin
    AGSGraphicsLayer *graphicsLayer = [AGSGraphicsLayer graphicsLayer];
    [self.mapView addMapLayer:graphicsLayer withName:@"GraphicsLayer"];
}

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
    
    // Release any cached data, images, etc that aren't in use.
}

- (void) viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    NSLog(@"Shutting down core location");
    [self.locationManager stopUpdatingLocation];
    self.locationManager = nil;
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)dealloc {
    self.mapView = nil;
    self.streetView = nil;
    self.imageryView = nil;
    self.reliefView = nil;
    
    [locateButton release];
    [super dealloc];
}

- (IBAction)toggleLayer:(id)sender {
    
    self.streetView.hidden = (((UISegmentedControl *)sender).selectedSegmentIndex != 0);
    self.imageryView.hidden = (((UISegmentedControl *)sender).selectedSegmentIndex != 1);
    self.reliefView.hidden = (((UISegmentedControl *)sender).selectedSegmentIndex != 2);    
}

- (IBAction)showLocation:(id)sender {
    NSLog(@"Show Location");
    
    CLLocation *location = self.locationManager.location;
    double lat = location.coordinate.latitude;
    double lon = location.coordinate.longitude;
    NSLog(@"%.3f, %.3f", lat, lon);
    
    double size = 0.05;
    AGSEnvelope *envelope = [AGSEnvelope envelopeWithXmin:lon - size 
                                                     ymin:lat - size
                                                     xmax:lon + size 
                                                     ymax:lat + size
                                         spatialReference:self.mapView.spatialReference];
    [self.mapView zoomToEnvelope:envelope animated:YES];
    
    // Get reference to the graphics layer
    id<AGSLayerView> graphicsLayerView = [self.mapView.mapLayerViews objectForKey:@"GraphicsLayer"];
    AGSGraphicsLayer *graphicsLayer = (AGSGraphicsLayer*)graphicsLayerView.agsLayer;
    
    // Clear graphics
    [graphicsLayer removeAllGraphics];
    
    // Create a marker symbol using the Location.png graphic
    AGSPictureMarkerSymbol *markerSymbol = [AGSPictureMarkerSymbol pictureMarkerSymbolWithImageNamed:@"Location.png"];
    
    // Create a new graphic using the location and marker symbol
    AGSGraphic* graphic = [AGSGraphic graphicWithGeometry:[envelope center]
                                                   symbol:markerSymbol
                                               attributes:nil
                                             infoTemplate:nil];
    
    // Add the graphic to the graphics layer
    [graphicsLayer addGraphic:graphic];
}

- (void) locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    NSLog(@"Core location has a new position");
    self.locateButton.enabled = YES;
}

- (void) locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    NSLog(@"Core location failed to get position");
    self.locateButton.enabled = NO;
}

#pragma mark AGSMapViewDelegate

//called when the map view is loaded (after the view is loaded) 
- (void)mapViewDidLoad:(AGSMapView *)mapView {
    
    //create extent to be used as default
    AGSEnvelope *envelope = [AGSEnvelope envelopeWithXmin:-124.83145667
                                                     ymin:30.49849464
                                                     xmax:-113.91375495
                                                     ymax:44.69150688
                                         spatialReference:mapView.spatialReference];
    
    //call method to set extent, pass in envelope
    [self.mapView performSelector:@selector(zoomToEnvelope:animated:) 
                       withObject:envelope
                       afterDelay:0.5];
}    

@end

Summary

In this post we looked at some options for utilizing Core Location with the ESRI ArcGIS iPhone API. ESRI’s AGSGPS class provides an easy to use convenience wrapper around Core Location, but it is not as flexible as working directly with Apple’s Core Location framework. An example was presented that demonstrates how to work with the Core Location framework and ESRI’s iPhone API. The example showed how to get the current location and zoom to it while showing a custom graphic on the map.

Click here to download the source code from this article.

I’m having a lot of fun learning about iPhone programming and ESRI’s iPhone API. I addition to testing in the simulator, I signed up for the Apple Developer Program so I can now run these apps on my iPod Touch. (The Mac Mini in the background is my dev box!)

iPodTouch

I hope you are enjoying these posts and finding the information helpful. If you have any suggestions, ideas or feedback, please leave them in the comments below.

Additional Resources

Tags: , , , ,

ArcGIS Server | ESRI | iPhone | Mobile

ESRI ArcGIS iPhone API – First Impressions

by James Richards May 04, 2010

The ESRI ArcGIS iPhone API was released to public beta today. Jeff Shaner blogged and tweeted about it this morning.

I downloaded the SDK this afternoon and took it for a spin. My first impressions are very favorable. Although the documentation is still a bit sparse in a few places, that’s to be expected for a first beta.

The SDK is another client API for consuming ArcGIS Server REST endpoints, and it works with versions 9.3.1 and 10.0. If you have worked with any of the other client APIs, you will already be familiar with the basic paradigm of interaction with the various REST services offered by ArcGIS Server.

The SDK Concepts Documentation provides a basic overview of the technology and includes a number of brief walkthroughs as well as short code samples illustrating how to perform common programming tasks with the API.

The installation also includes six sample applications which are installed into your ~/Library/SDKs/Samples folder. Studying these sample apps is a good way to jumpstart your familiarity with the API.

But enough talk already, let’s see some code! [more]

After following the My First iPhone Application tutorial,  I decided to jump in and modify the application to improve it in a some specific ways:

  • Add a button bar to toggle three base map types: Streets, Aerial Imagery, and Shaded Relief Map
  • Zoom to a predefined initial extent on application startup
  • Support any device rotation

I won’t spend a lot of time describing everything here. I’ll just show a few screen snapshots with the source code and make everything available for download.

Here are some screen snapshots of the app running in the simulator:

StreetView     ImageryView     ReliefView

Rotated

Here is the MyFirstMapAppViewController.h header file:

#import <UIKit/UIKit.h>
#import "AGSiPhone.h"

#define kTiledStreetMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer"
#define kTiledImageryMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer"
#define kTiledReliefMapServiceURL @"http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_ShadedRelief_World_2D/MapServer"

@interface MyFirstMapAppViewController : UIViewController<AGSMapViewDelegate> {
    AGSMapView *_mapView;
    
    UIView *_streetView;
    AGSTiledMapServiceLayer *_streetLayer;
    
    UIView *_imageryView;
    AGSTiledMapServiceLayer *_imageryLayer;

    UIView *_reliefView;
    AGSTiledMapServiceLayer *_reliefLayer;
    
}

@property (nonatomic, retain) IBOutlet AGSMapView *mapView;

@property (nonatomic, retain) UIView *streetView;
@property (nonatomic, retain) AGSTiledMapServiceLayer *streetLayer;

@property (nonatomic, retain) UIView *imageryView;
@property (nonatomic, retain) AGSTiledMapServiceLayer *imageryLayer;

@property (nonatomic, retain) UIView *reliefView;
@property (nonatomic, retain) AGSTiledMapServiceLayer *reliefLayer;

- (IBAction)toggleLayer:(id)sender;

@end

(Sorry, this is my first post about iPhone programming and I haven’t figured out how to highlight the syntax for Objective-C yet!)

And here is the MyFirstMapAppViewController.m implementation file:

#import "MyFirstMapAppViewController.h"

@implementation MyFirstMapAppViewController

@synthesize mapView = _mapView;
@synthesize streetView = _streetView;
@synthesize streetLayer = _streetLayer;
@synthesize imageryView = _imageryView;
@synthesize imageryLayer = _imageryLayer;
@synthesize reliefView = _reliefView;
@synthesize reliefLayer = _reliefLayer;

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.mapView.mapViewDelegate = self;
    
    self.streetLayer = [AGSTiledMapServiceLayer tiledMapServiceLayerWithURL:[NSURL URLWithString:kTiledStreetMapServiceURL]];
    self.streetView = [self.mapView addMapLayer:self.streetLayer withName:@"Street"];
    self.streetView.hidden = NO;

    self.imageryLayer = [AGSTiledMapServiceLayer tiledMapServiceLayerWithURL:[NSURL URLWithString:kTiledImageryMapServiceURL]];
    self.imageryView = [self.mapView addMapLayer:self.imageryLayer withName:@"Imagery"];
    self.imageryView.hidden = YES;

    self.reliefLayer = [AGSTiledMapServiceLayer tiledMapServiceLayerWithURL:[NSURL URLWithString:kTiledReliefMapServiceURL]];
    self.reliefView = [self.mapView addMapLayer:self.reliefLayer withName:@"Relief"];
    self.reliefView.hidden = YES;
        
}

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
    
    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload {
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)dealloc {
    self.mapView = nil;
    self.streetView = nil;
    self.streetLayer = nil;
    self.imageryView = nil;
    self.imageryLayer = nil;
    self.reliefView = nil;
    self.reliefLayer = nil;
    
    [super dealloc];
}

- (IBAction)toggleLayer:(id)sender {
    
    self.streetView.hidden = (((UISegmentedControl *)sender).selectedSegmentIndex != 0);
    self.imageryView.hidden = (((UISegmentedControl *)sender).selectedSegmentIndex != 1);
    self.reliefView.hidden = (((UISegmentedControl *)sender).selectedSegmentIndex != 2);    
}

#pragma mark AGSMapViewDelegate

//called when the map view is loaded (after the view is loaded) 
- (void)mapViewDidLoad:(AGSMapView *)mapView {
    
    //create extent to be used as default
    AGSEnvelope *envelope = [AGSEnvelope envelopeWithXmin:-124.83145667
                                                     ymin:30.49849464
                                                     xmax:-113.91375495
                                                     ymax:44.69150688
                                         spatialReference:mapView.spatialReference];
    
    //call method to set extent, pass in envelope
    [self.mapView performSelector:@selector(zoomToEnvelope:animated:) 
                       withObject:envelope
                       afterDelay:0.5];
}    

@end

There are a couple of points to note about how things are wired up in Interface Builder.

The UISegmentedControl’s Value Changed event is hooked up to the File’s Owner’s toggleLayer function.

IB1

And the UISegmentedControl’s Autosizing is set to bottom center. By configuring the control this way in Interface Builder, we do not need to write any code to handle placement of the UISegmentedControl when the view rotates.

IB2

Summary

Well, that about covers everything for my first experience with the ESRI iPhone SDK. All in all, I’d say it looks like another great client API for use with ArcGIS Server. For those of us who have been wanting to create native iPhone apps on the ESRI stack, the wait is over!

I hope you enjoyed this brief tour of ESRI’s latest offering.

Click here to download the source code from this article.

Additional Resources

Tags: , , ,

ArcGIS Server | ESRI | Mobile | iPhone

My Favorite Tweets from the ESRI BPC / Devsummit - Day 5

by James Richards March 25, 2010

Presenting the final day of my favorite tweets from the ESRI Business Partners Conference / Developer Summit. Many thanks to all the Tweeps who kept the rest of us informed. I hope my small role of documenting my favorites has helped a few others.

  • http://twitpic.com/1atozp - Empty halls at #devsummit. Guess the party last night was a success. #earlybirdsession - via @martenhogeweg
  • #MVC, test-driven development & #IOC shown with #Cairngorm 3 #devsummit #flex #as3 - via @dafkobyte
  • Extending the tiledmapservicelayer in silverlight with @rex_hansen using openstreetmap. Very cool. #devsummit - via @vtforester
  • @SharpGIS Dissin' the Flex folks. Too funny. I'm thinking Dodgeball game...flex team vs silverlight team. #devsummit - via @vtforester
  • Yay Jeremy! "Don't put ArcMap inside firefox" #devsummit #usability - via @bnoyle
  • For those interested in JS API 2 public beta...you need to get the bits from ESRI blogs. not integrated into resource centers yet #devsummit - via @bnoyle
  • Idea for next #DevSummit - API team should show nice, well designed workflow apps, and then go through how to build'em and release src - via @dbouwman
  • heard some people wondering what happened to gdb versioning. indeed no talk by ESRI at #devsummit -all web editing going directly to the gdb - via @oseidel
  • New Geolocator stuff is impressive. Configurable, Grammar-based with a plugin model.  Unicode/internationalised. Total rewrite. #DevSummit - via @geeknixta
  • Learn more about the forthcoming #ESRI ArcGIS Explorer Online from these #devsummit videos: http://bit.ly/bQ6mYW - via @bernszukalski
  • ArcGIS 10 Final release in June #devsummit - via @RealIdahoBoy
  • arcgis 10 prerelease available for all EDN #devsummit - via @Gazymodo
  • Everyone heard, ezre said Fedora 12 support on its way. #devsummit - via @cageyjames
  • @cageyjames fedora not at 10, that is post 10 #devsummit - via @spangrud
  • Arcgisserver 10 to get openid support in the future! #devsummit - via @RealIdahoBoy
  • #ArcGIS SDK for #iPhone: map layers, overlay graphics, search/id, locate address, collect data & tasks. #devsummit - via @dafkobyte
  • Disappointed that feature service web editing is only supported using SDE. Small-ish shops could really benefit from this. #devsummit - via @BrightRain
  • Last day of #devsummit. Thanks to everyone at #ESRI and I look forward to seeing you all next year. - via @calvinit21
  • at Palm Springs airport. goodbye #devsummit - via @Gazymodo

For newcomers to the series, here are my day 1, day 2day 3 and day 4 favorites.

Enjoy!

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ESRI

My Favorite Tweets from the ESRI BPC / Devsummit - Day 4

by James Richards March 24, 2010

Presenting day 4 of my favorite tweets from the ESRI Business Partners Conference / Developer Summit. A lot more tweets coming through today with the #devsummit hash tag than there were the first two days with the #esri_bpc hash tag. My unscientific conclusion is that developers use Twitter more than business types.

  • @trbaker Where are your #Twitter followers? GeoTweeters: http://bit.ly/lscto #devsummit #gis #socialnetworking - via @geoinformacao
  • Sweet! We wom the mashup challenge! Plus big shout out to @dbouwman from #esri #devsummit - via @bnoyle
  • #ESRI #mashup challenge winners now online at http://bit.ly/5jG8Dz #DevSummit #esridevsummit - via @giseducation
  • Recently "mashup," now "cloud." Keywords we get to listen to for a while. #devsummit - via @RealIdahoBoy
  • David Chappell: "Startups love cloud platforms. They allow startups to fail fast and cheaply (or even free)." #devsummit - via @ChrisSpagnuolo
  • Hopefully Chappell will show how expensive windows azure is. #devsummit - via @cageyjames
  • #esri story on cloud computing is good, but still need more info on cost/time to scale and a move away from ELA only needed #devsummit - via @bnoyle
  • Spatial data stored in user tables, can be accessed via SQL #devsummit - via @TrippingTheBits
  • It is odd to me tho that complex maps perform better using SHP in AGS. #devsummit - via @kirrilian
  • The Flex editor is nice, but worry some will forget to use tools in the context of a workflow. Don't re-create ArcEditor in Flex! #DevSummit - via @dbouwman
  • New to ArcGIS 10: Query Layers = layers based on real SQL queries! #devsummit - via @TrippingTheBits
  • Sounds like FGDB API is still a ways off #devsummit - via @cageyjames
  • No support for Annotation, Relationships, Networks, Topologies, Representations, Terrains and Parcel Fabrics in FGDB API #devsummit - via @cageyjames
  • Sweet. Ed architecting a SQL compatible geocode soln. Off the cuff in response to question #devsummit - via @bnoyle
  • Browser usage in demos: Firefox = most, Chrome = a couple, IE = NONE. #devsummit - via @gadtweet
  • REST extension URLs: /serverUrl/exts/extName/extMethod #devsummit - via @TrippingTheBits
  • Woah, add AGS Inet connection to ArcMap, right-click, choose Edit Features, makes local copy, sync back to db #devsummit - via @TrippingTheBits
  • #devsummit ver 2 of esri #silverlight API built on #VS2010 and #SL4. New widgets for editing,time,and feature data editing in toolkit. - via @cfemmer
  • #devsummit @SharpGIS is spreading the #SL goodness. woot for binding and commanding! - via @jrockers
  • Playing with ArcGIS Explorer sdk...pretty awesome! A lot more control than I expected! #devsummit - via @NateStrout
  • iPhone SDK for AGS Server interesting. If only I had a Mac for development.... #devsummit - via @northpointgis
  • MS Surface demo, picking AGOL sources and dropping onto a map is slick! #DevSummit - via @geeknixta
  • #devsummit Iphone SDK will work with iPad and iTouch too. SDK assumes always on connection. - via @jshek

For newcomers to the series, here are my day 1, day 2 and day 3 favorites.

Enjoy!

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ESRI

My Favorite Tweets from the ESRI BPC / Devsummit - Day 3

by James Richards March 23, 2010

Presenting day 3 of my favorite tweets from the ESRI Business Partners Conference / Developer Summit. I missed most of the morning due to being on a client site. But here are my faves from the afternoon.

  • @MapsRus I was in the Server session at the #ESRI_BPC - Nothing new in ADF for 10 . Only bug fixes. All but dead. #webADF #DevSummit - via @dbouwman
  • REST Server Object Extension sounds easy, implement the two method IRESTRequestHandler #devsummit - via @TrippingTheBits
  • At desktop add-in session at #devsummit. No more COM wireup with extensions. Fantastic! - via @BrightRain
  • #devsummit @ajhaddad just said three very exciting letters, "MEF" - via @jrockers
  • @rex_hansen showing us how to use Expression Blend to make a Silverlight app. Great starter session. API is nicely integrated. #DevSummit - via @geeknixta
  • At the Silverlight WPF session where Rex @rexhansen is showing the real power of Binding #devsummit - via @alpascual
  • @dbouwman just called me a troublemaker in his presentation. #sweet #devsummit - via @cageyjames
  • ArcGIS for Silverlight API 2.0 public beta coming in April. Supporting VS2010, Expression Blend 4, Silverlight 4, .NET 3.5 & 4. #DevSummit - via @geeknixta
  • Wow. Presenter says "filegdb faster on linux than sde". Goes against everything esri has said for years. #devsummit - via @geodatabase 
  • Videos of the #ESRI_BPC demos are now available. The ArcGIS Server on Amazon demo will be posted tomorrow. http://is.gd/aUZcV - via @ESRI_BPC
  • Where are the Avenue sessions? #devsummit - via @odoenet

Not too many tweets using the #esri_bpc hash tag any more. Most tweeps have moved over to #devsummit.

For newcomers to the series, here are my day 1 and day 2 favorites.

Enjoy!

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ESRI

My Favorite Tweets from the ESRI BPC / Devsummit - Day 2

by James Richards March 22, 2010

Presenting day 2 of my favorite tweets from the ESRI Business Partners Conference / Developer Summit:

  • There will be a new workspace type in 10 - "SQL Workspace" for direct SQL queries (spatial/nonspatial) #devsummit - via @eriknybergNET
  • ArcGIS.com will be a great resource for #maps #WebApps #mobileApps and tools. #esri_bpc - via @cmcginty
  • Like the features of ArcGIS.com that allow you to share with everyone or by limiting to groups. Very useful for info prep. #esri_bpc - via @cmcginty
  • @mraad shows usage of local Shapefiles, and collaborative web map editing environment. #webmap #devsummit - via @dafkobyte
  • ArcGIS JavaScript API 2.0 public beta made available today http://tinyurl.com/yez986j #ESRI #devsummit - via @SterlingGIS
  • AGS 10 (JavaScript 2.0 API) looks great- editing and temporal data display. Nice to see all those oil & gas well app samples. #devsummit - via @dropstones
  • New AGS 'FeatureServer' will allow for feature insert & update via REST & SOAP APIs #devsummit - via @TrippingTheBits
  • Android sdk will be next big push after Arc10 release #Esri_bpc #devsummit - via @mapitout
  • details being presented on new ESRI certification program #ESRI_BPC - via @DaleLoberger
  • You know you're a bit of a nerd when you pick up a Spock bobblehead. #devsummit #swag - via @adamjpfister

Tweets seemed to peter out around 4pm today. I guess everyone was hitting the bar by then...

For newcomers to the series, day 1 favorites are here.

Enjoy!

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ESRI | Planet GS

My Favorite Tweets from the ESRI BPC / Devsummit - Day 1

by James Richards March 21, 2010

For those of you (like me) who couldn't make it to the ESRI Business Partner Conference / Developer Summit, you can follow the action on Twitter with the hash code #esri_bpc. You should also keep an eye on #devsummit since @dbouwman seems to have an aversion to typing underscores.

Here are a few of my favorite tweets from day 1:

  • #esri_bpc: Where ESRI decides when and how to eat its offspring. - via @howardbutler
  • 4min to have AGS set-up in the cloud? Wow! That should drop some billable hours... #esri_bpc - via @spanaut
  • ArcGIS in the Amazon cloud will work just like any other platform - except for the loading tons of data ;-) #esri_bpc - via @cmcginty
  • Dear ESRI, stop saying it takes 4 min to set up ArcGIS on AWS. #false #esri_bpc - via @cageyjames
  • Both an iPhone app for ArcGIS and an iPhone SDK will be available with ArcGIS 10 #ESRI_BPC - via @jeroenvanwinden
  • No support for legend /toc in rest api at 10... This is a GOOD thing! #devsummit - via @dbouwman
  • Just had demo of SQL Azure Spatial from Spatial Ed at #esri_bpc -- impressive. See Ed's blog http://bit.ly/bbNDoE + #FME just *works* on it - via @DaleAtSafe
  • @ESRI should be paying @dbouwman & @cageyjames some coin for their coverage of AGS10 at #DevSummit. <foil hat on> - via @tokumin
  • As compelling at this session is, I'm gonna install v10 beta on my laptop... #multi-tasking #DevSummit - via @dbouwman

Enjoy!

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ESRI | Planet GS

How To: Display an ArcGIS Server Cached Tile Layer as a Custom Map Type with the Google Maps API for Flash

by James Richards July 06, 2009

Overview

This is the third post in a series where I discuss techniques for interacting with the ArcGIS Server REST API from within a Flex 3 application built with the Google Maps API for Flash. The first and second posts presented and refined an example that demonstrated how to stream features from ArcGIS Server and overlay them on top of Google Maps data. This post demonstrates how to display an ArcGIS Server cached tile layer as a custom map type with the Google Maps API for Flash.

Sample Application Concepts

The sample application works as follows:

  • The Google Maps API for Flash is embedded in a Flex 3 application.
  • A cached tile layer representing Land Base features for Portland, Oregon is served via an ArcGIS Server Map Service, accessible via ArcGIS Server’s REST API.
  • The cached tile layer appears as a custom map type in the Google Maps API for Flash User Interface.
  • The cached tile layer is displayed at zoom levels 0 - 19.

Here are a couple of screen shots of the sample application. The first shows the application with the custom “Land Base” map type selected. The second shows the application with the normal map type selected.

image

image

Live example is here, and source code is here. [more]

Discussion

MXML File

Starting with a basic Flex Application, we have a single map with a specified “map ready” event:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
    xmlns:gm="com.google.maps.*"
    backgroundGradientColors="[0xFFFFFF, 0xAAAAAA]"
    height="100%" width="100%" viewSourceURL="srcview/index.html">
    <gm:Map id="map"
        width="100%"
        height="100%"
        key="(Your API Key)"
        mapevent_mapready="map_mapReady(event)" />
    <mx:Script>
        // Omitted for clarity
    </mx:Script>
</mx:Application>

In the map_mapReady function we create an instance of the custom tile layer, specifying the URL endpoint of the cached tiles, the minimum and maximum zoom levels, and the copyright text. Then we create a new map type using the custom tile layer instance. Next we add the usual map controls, and finally we initialize the map using the new map type.

private function map_mapReady(event:Event):void {
    // Create custom tile layer
    var baseUrl:String = http://sampleserver1.arcgisonline.com/ +
        "ArcGIS/rest/services/Portland/ESRI_LandBase_WebMercator/MapServer";
    var copyright:String = "Taxlots, Zoning © Oregon METRO RLIS; " +
        "Buildings © City of Portland Planning"; 
    var tileLayer:TileLayer = new TileLayer(baseUrl, 0, 19, copyright);

    // Create custom map type and add to map
    var mapType:IMapType = new MapType([tileLayer], map.MERCATOR_PROJECTION, "Land Base");
    map.addMapType(mapType);

    // Add map controls
    var mtc:MapTypeControl = new MapTypeControl();
    map.addControl(mtc);
    var pc:PositionControl = new PositionControl();
    map.addControl(pc);
    var zc:ZoomControl = new ZoomControl();
    map.addControl(zc);
    var sc:ScaleControl = new ScaleControl();
    map.addControl(sc);
    var omc:OverviewMapControl = new OverviewMapControl();
    map.addControl(omc);

    // Initialize map. Use custom tile layer for the initial map type           
    map.setCenter(new LatLng(45.520211, -122.65553), 17, mapType);
}

The custom tile layer is implemented with the reusable TileLayer class and its companion Tile utility class. The basic design for these classes comes from Pamela Fox’s custom tile layer sample in the Google Maps API for Flash Demo Gallery.

The TileLayer constructor takes four arguments: the URL endpoint of the cached tiles, the minimum zoom level, the maximum zoom level, and the copyright text. Our example uses an ESRI sample server that has a Land Base cached tile service for Portland, Oregon. 

We determine the appropriate values for the constructor’s arguments by exploring the MapServer REST API using the interactive SDK . The MapServer is hosted at: http://sampleserver1.arcgisonline.com/arcgis/rest/services

image

By drilling down into the Portland Folder and the associated MapServices, we learn about the functionality and data layers that are available for consumption. If we drill down to the Portland/ESRI_LandBase_WebMercator MapServer, we can gather the information we need to fill in the above mentioned TileLayer constructor.

image

First, we need to check to make sure that the MapServer is cached. Look at the Single Fused Map Cache property and make sure it is set to true. Next, verify that the MapServer uses the Google Maps (and Virtual Earth) tiling scheme by making sure the Spatial Reference is set to 102113 (Web Mercator), the Width and Height are 256 pixels, and the DPI is 96.

If you are designing your own map cache to overlay on top of Google Maps, be sure to read the following information in the ESRI online documentation (depending on your platform):

To determine the base URL constructor argument, look at the URL in the browser’s address bar. The URL should end with “MapServer”.

image

To determine the minimum and maximum zoom levels, scroll down and look at the Tile Info - Levels of Detail section. The first Level ID in the list is the minimum zoom level (in this case 0) and the last Level ID is the maximum zoom level (in this case 19).

image

Finally, the copyright parameter can be anything you deem appropriate. In this case, I abbreviated the information found in the Copyright Text property of the MapServer.

TileLayer Class Implementation

Moving on to the TileLayer class implementation, here is the code:

// Custom tile layer for displaying ArcGIS Server cached tiles
// in a Google Maps API for Flash application.
public class TileLayer extends TileLayerBase
{
    private var baseUrl:String;
    private var minResolution:Number;
    private var maxResolution:Number;

    // Constructor
    public function TileLayer(baseUrl:String, minResolution:Number,
                          maxResolution:Number, copyright:String) {
        // Save the options
        this.baseUrl = baseUrl;
        this.minResolution = minResolution;
        this.maxResolution = maxResolution;

        // Add copyright information.
        var copyrightCollection:CopyrightCollection = new CopyrightCollection();
        copyrightCollection.addCopyright(new Copyright("TileLayer",
            new LatLngBounds(new LatLng(-180, 90), new LatLng(180, -90)),
            0, copyright));
        super(copyrightCollection);
    }

    // Return the coarsest zoom level. Provides information necessary
    // to adjust the boundaries of the zoom level control when this 
    // layer is included in a custom map type.
    public override function getMinResolution():Number {
        return minResolution;
    }

    // Return the finest zoom level. Provides information necessary to
    // adjust the boundaries of the zoom level control when this layer
    // is included in a custom map type.
    public override function getMaxResolution():Number {
        return maxResolution;
    }

    // Creates and loads a tile (x, y) at the given zoom level.
    public override function loadTile(tilePos:Point, zoom:Number):DisplayObject {
        return new Tile(baseUrl, tilePos, zoom);
    }       
}

As you can see, the class is pretty simple. It extends the Google Maps API’s TileLayerBase abstract base class, which does most of the work. According to the Google Maps API for Flash Documentation, sub-classes must override the loadTile() method; however, overriding the other methods is optional. The loadTile() method must return a DisplayObject that represents the tile.

Tile Class Implementation

In the loadTile() method implementation, we defer to the Tile utility class, which is defined as follows:

// Custom tile for displaying ArcGIS Server cached tiles
// in a Google Maps API for Flash application.
public class Tile extends Sprite
{
    // Constructor
    public function Tile(baseUrl:String, tilePos: Point, zoom:Number)
    {
        // Construct the url to the ArcGIS Server tile:
        // http://<path to map service>/tile/<zoom level>/<y>/<x>
        var tileUrl:String = baseUrl + "/tile/" + zoom.toString() + "/" +
            tilePos.y.toString() + "/" + tilePos.x.toString();
        trace(tileUrl);

        // Load the tile and add it to the sprite as a child
        var loader:Loader = new Loader();
        loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
        loader.load(new URLRequest(tileUrl));
        addChild(loader);
    }

    // Error handler when a tile cannot be loaded by the loader.
    public function ioErrorHandler(event:IOErrorEvent):void {
        // If the tile was not found, just load an empty sprite
        // so nothing draws.
        addChild(new Sprite());
    }
}

The Tile class extends Sprite, which in turn inherits from DisplayObject. Therefore, we can return an instance of the Tile class from the loadTile() method in the TileLayer class. The Tile class’s constructor builds a URL to the tile as served by the ArcGIS Server REST API. The URL pattern for accessing tiles through the REST API is: http://<path to map service>/tile/<zoom level>/<y>/<x>

Once the URL string is created, a flash Loader is used in concert with a URLRequest object to load the tile image and add it as a child to the Sprite. If the tile is not found and an error is thrown, we simply add an empty Sprite instead so nothing draws. Alternatively, we could load some kind of "tile not found" graphic, as shown by Pamela Fox’s custom tile layer sample in the Google Maps API for Flash Demo Gallery.

Wrap Up

This post has demonstrated how to display an ArcGIS Server cached tile layer as a custom map type with the Google Maps API for Flash. The TileLayer and Tile classes are reusable. To add an ArcGIS Server cached tile layer to your project, simply copy the classes as-is and modify the code shown in the map_mapReady event to use your cached MapServer.

Live example is here, and source code is here.

Resources

Downloads
Documentation and Sample Servers
Blogs, Forums and Code Galleries

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ArcGIS Server | Flex 3 | Google Maps | How To | Planet GS | REST

ArcGIS Server WebADF: Adjusting the Zoom Scale for Find Address Task Results

by James Richards July 02, 2009

Overview

When working with the Find Address Task in the ArcGIS Server WebADF, the default zoom scale that is displayed when the user zooms to a found address might not be what you want. This article discusses how to change it using the ZoomToPointFactor property. [more]

Background

Let’s assume that you have a WebADF application with some Map Layers and a Find Address Task that is configured to use a Geocoding Service. This could be an application that you created from scratch in Visual Studio, or one that you created with ArcGIS Server Manager.

After entering an address:

image

The results are shown in the Task Results panel. From there you can right click on an address and choose Zoom To:

image

This will zoom the map to an area centered on the address point. The problem is that scale to which the map is zoomed might not be what you want. Often it’s zoomed out too far.

Solution

To adjust the zoom scale to your liking, add the ZoomToPointFactor property to the esri:TaskResults element on the ASP.NET Page hosting the application.

If you created the application with ArcGIS Server Manager using the default options, this would be found in the Default.aspx file in the C:\inetpub\wwwroot\[YourApplicationName] directory.

Open this file and search for the esri:TaskResults tag, then add the ZoomToPointFactor property and give it a numeric value. In the example below, I’ve set the property to “1000”.

image ArcGIS Server will divide the width and height of the map by this value when zooming to a point. For this example, the zoom area will be 1/1000th of the full extent. The larger the ZoomToPointFactor, the further in that the map will zoom. You will need to experiment to find the ratio that works best, as the full extent can vary greatly depending on the data in your application.

Also note that if you have any cached map services in your application, ArcGIS Server will snap to the cache scale that is closest to the calculated map extent. Consequently, you might not see the map extent change if you don’t modify the ZoomToPointFactor property by a large enough value to jump to another scale.

Resources

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.NET | ArcGIS Server | How To | Planet GS | WebADF

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James Richards

Hi, I'm James Richards the CTO and co-founder of Artisan Global LLC. We make location-aware mobile apps with maps. I'm the author of QuakeFeed and I helped launch Zaarly at LASW Feb 2011. I also enjoy surfing, snowboarding, golfing, yoga, and music. I love my family: Linda, Sequoya and our cats Remy and Twiggy. Thanks for stopping by, I hope you find something helpful here.

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