Latest Contributions by PaulLohr

I have some code that adjusts the zoom level of the map based on a zoom factor. The problem is the map does not zoom in or out from the center but slightly offset from the center. The map content shifts toward the upper left each time a zoom out occurs. The map shifts toward the lower right when a zoom in occurs. The map has a UITextField (named scaleLabel) where it displays the current scale and the user can type in the desired scale in this textField (for example, the user might type in 600 to get 1"=600'). After dismissing the keyboard, the map adjusts to the new scale. Please note that this posting only shows the code that I believe to be relevant. If you need more, I'd be glad to add it. Header file: #import <UIKit/UIKit.h> #import "ArcGIS.h" @interface MapView : UIViewController <UITextFieldDelegate, AGSMapViewLayerDelegate, AGSMapViewTouchDelegate> {     AGSMapView *_mapView; UITextField *scaleLabel; UIView *inputAccessoryView; float scaleCurrentValue; } // class properties @property (nonatomic, retain) IBOutlet AGSMapView *mapView; @property (nonatomic, retain) IBOutlet UITextField *scaleLabel; // could not use retain (since a float is not an object?) @property (nonatomic, assign) float scaleCurrentValue; // method prototypes -(void)zoomToGraphicsLayer; -(void)respondToEnvChange:(NSNotification *)notification; -(NSDictionary *)findMapCenter; -(void)zoomMapByChangingScaleText; @end Selected methods from the implementation file: In the code below, I setup the notifications to listen for changes in the zoom level or map's extent. -(void)mapViewDidLoad:(AGSMapView *)mapView { // register for "MapDidEndPanning" notifications [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(respondToEnvChange:) name:@"MapDidEndPanning" object:nil]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(respondToEnvChange:) name:@"MapDidEndZooming" object:nil]; // scaleLabel is a UITextField that shows and allows the user to change the map's scale. scaleLabel.text = [NSString stringWithFormat:@"%.0f", (self.mapView.mapScale / 2.54) / 12]; } Below is how we calculate the center of the map. We need centerX and centerY to be used in zoomWithFactor's atAnchorPoint argument. Notice that this method is called by zoomMapByChangingScaleText and this method returns an NSDictionary. -(NSDictionary *)findMapCenter { NSDictionary *mapCenterMethod; float mapCenterX = ( (self.mapView.envelope.xmax - self.mapView.envelope.xmin ) / 2 ) + self.mapView.envelope.xmin; float mapCenterY = ((self.mapView.envelope.ymax - self.mapView.envelope.ymin) / 2) + self.mapView.envelope.ymin; mapCenterMethod = [NSDictionary dictionaryWithObjectsAndKeys:         @"centerX", [NSNumber numberWithFloat:mapCenterX],         @"centerY", [NSNumber numberWithFloat:mapCenterY], nil]; NSLog(@"mapCenterMethod: %f; %f",mapCenterX, mapCenterY); // put X and Y values into an NSDictionary return mapCenterMethod; } Below is where the zoom operation takes place. -(void)zoomMapByChangingScaleText { if ( self.scaleCurrentValue != [scaleLabel.text floatValue] ) { // run the findMapCenter method. // put the return value in an NSDictionary. NSDictionary *mapCenter = [self findMapCenter]; // get the new value in the UITextField since the done button was tapped. float newScaleValue = [scaleLabel.text floatValue]; // calculate the zoom factor. float zoomFactor = newScaleValue / self.scaleCurrentValue; [self.mapView zoomWithFactor:zoomFactor      atAnchorPoint:CGPointMake([[mapCenter objectForKey:@"centerX"] floatValue], [[mapCenter objectForKey:@"centerY"] floatValue])        animated:YES];   [scaleLabel resignFirstResponder]; } else // scale did not change...hide the keyboard. {   [scaleLabel resignFirstResponder];   } } Thank you for any help, Paul Lohr ... View more

I would like to set a maximum zoom level for my map. Currently I am using AGSGraphicsLayer:zoomToEnvelope to automatically zoom to a set of AGSGraphics but it often zooms in too far (Map Data Not Yet Available). My base layer is an AGSTiledMapServiceLayer. I would think there would be a "maxZoomLevel" read/write property for AGSMapView but I'm not seeing it or anything similar. I found this thread that mentions AGSLOD but I don't really understand the code: http://forums.arcgis.com/threads/7150-How-to-map-zoom-in-level Thank you for any help, Paul Lohr ... View more

I have not been able to find any samples that use AGSGeometryEngine projectGeometry: toSpatialReference:. Xcode is telling me that it cannot find a method named projectGeometry:toSpatialReference. The warning messages are: warning: Semantic Issue: Class method '+projectGeometry:toSpatialReference:' not found (return type defaults to 'id') 'AGSGeometryEngine' may not respond to '+projectGeometry:toSpatialReference:' Here is the code that generates the warning: (please note that myPoint is an AGSPoint...a type of AGSGeometry with it's spatial reference being 4326 (WGS1984)) AGSPoint *myPointReprojected; myPointReprojected = [AGSGeometryEngine projectGeometry:myPoint                                    toSpatialReference:[AGSSpatialReference webMercatorSpatialReference]]; Thank you for even the smallest amount of help, Paul Lohr ... View more