topic Re: How to zoom to a point in map in ArcGIS API for Silverlight Questions

How to zoom to a point in map

JobyGeorge — Tue, 24 Apr 2012 05:35:45 GMT

Hi

I have created an application in silverlight using arcgis api. In that I am saving the location in map using map points.

I got the map points while I try to save the record.

When i try to edit the same record I want to zoom to the particular location. How can I do this

<Grid x:Name="LayoutRoot" Margin="2">
        <Grid.Resources>
            <esri:PictureMarkerSymbol x:Key="PinPictureMarkerSymbol" Source="/UIControls.AccidentRecordForm;component/Images/Delete_2.png" />
        </Grid.Resources>
        <esri:Map MouseClick="Map_MouseClick" x:Name="MyMap">
            <esri:Map.Layers>
                <esri:ArcGISTiledMapServiceLayer Url="http://www.darb.ae/ArcGIS/rest/services/BaseMaps/DOT_StreetMap_En/MapServer"/>
                    <esri:GraphicsLayer ID="MyGraphicsLayer">
                            <esri:GraphicsLayer.Graphics >
                        <esri:Graphic Symbol="{StaticResource PinPictureMarkerSymbol}">
                                </esri:Graphic>
                            </esri:GraphicsLayer.Graphics>
                        </esri:GraphicsLayer>

                    </esri:Map.Layers>
        </esri:Map>
    </Grid>

                    MapPoint mapPoint=new MapPoint(Convert.ToDouble(crashForm.tbLocationEasting.Text), Convert.ToDouble(crashForm.tbLocationNorthing.Text));
                    GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
                    Graphic graphic = new Graphic()
                        {
                            Geometry = mercator.FromGeographic(mapPoint),
                            Symbol = LayoutRoot.Resources["PinPictureMarkerSymbol"] as Symbol
                        };
                    graphicsLayer.Graphics.Clear();
                    graphicsLayer.Graphics.Add(graphic);

this is the code where I add graphics to the map whle editting.

How can I zoom or focus to this location?
Please help.

Re: How to zoom to a point in map

DeminHu — Tue, 24 Apr 2012 14:19:39 GMT

MyMap.ZoomTo ( pt);

If you don't want to Zoom too close, you can do something like the following:
           Envelope env = new Envelope();
          env.SpatialReference = MyMap.SpatialReference;
          env.XMax = pt.X + 500;
          env.YMax = pt.Y + 500;
          env.XMin = pt.X - 500;
          env.YMin = pt.Y - 500;
          MyMap.ZoomTo(env);

Re: How to zoom to a point in map

JenniferNery — Tue, 24 Apr 2012 18:53:23 GMT

This is a related thread: http://forums.arcgis.com/threads/13749-how-to-Zoom-to-point

Re: How to zoom to a point in map

JobyGeorge — Wed, 25 Apr 2012 09:19:16 GMT

MyMap.ZoomTo ( pt);

If you don't want to Zoom too close, you can do something like the following:
           Envelope env = new Envelope();
          env.SpatialReference = MyMap.SpatialReference;
          env.XMax = pt.X + 500;
          env.YMax = pt.Y + 500;
          env.XMin = pt.X - 500;
          env.YMin = pt.Y - 500;
          MyMap.ZoomTo(env);

Hi deminhu,

by using this I am able to set the focus to that point. Now I am facing an issue, that is when I trying to focus at first time without loading the map the spatial reference become null so
It wont focus to the correct location. I also tryed to hard cord the spatial reference but the issue continues.
Please help.

Is there any event in map which will fire after loading the map so that I can run the code at that time?

Re: How to zoom to a point in map

JenniferNery — Wed, 25 Apr 2012 16:09:36 GMT

You can subscribe to Map.PropertyChanged (e.PropertyName == "SpatialReference") or Map.Layers.LayersInitialized event.

Re: How to zoom to a point in map

dotMorten_esri — Wed, 25 Apr 2012 16:18:53 GMT

Is there any event in map which will fire after loading the map so that I can run the code at that time?

If you want to set the extent prior to the map is ready for zooming, just set the extent instead of zooming.
ie. myMap.Extent = myNewExtent;

Re: How to zoom to a point in map

JobyGeorge — Mon, 30 Apr 2012 09:05:15 GMT

If you want to set the extent prior to the map is ready for zooming, just set the extent instead of zooming.
ie. myMap.Extent = myNewExtent;

By using this I am able to solve the problem.

focusing after initializing the layer is of no use if we want to zoom to a point before loading the map.