nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

ArcGis "Zoom To Layer" functionality in ESRI Silverlight API

AlexanderOvsyankin

Hello Experts,

I have sde database and I published a dynamic service with 1 layer in it. The layer displaying data from sde spatial view.

When my map is initializing I want to zoom to the layer extent (extent of all features in this layer).

I have some options on how to do it:
1. Set full extent for the Data Frame in mxd before publishing and then zoom to
ArcGISDynamicMapServiceLayer.FullExtent. It's not a good aproach for me since it is a dynamic service and data are loading to sde by another application, so after data will arrive this extent will not be actual.

2. Set current extent in mxd to full layer extent before publishing and then zoom to
ArcGISDynamicMapServiceLayer.InitialExtent. It's not a good aproach again due to the same reason as described above.

3. Run query against the layer, get features, go throw the list of results and using feature.geometry - create an extent. But layer contains much more than 500 (recommended by ESRI amount of features to be returned by the query ) objects (~100 000) and in result my calculated extent will not present the real extent of data, but just a portion of it. Of course I can change the maximum amount of features to be returned by the query

, but my map will be extremely slow since I will need to load all 100 000 features on the client side

...

Additionally, I am filtering my layer using LayerDefinition and I want to be able to zoom into filtered layer too (in this case aproaches 1 and 2 don't work at all)...

4. Not sure, but: I can create my own geoprocessing service to get the extent of the layer on the server side and use it on the client side to zoom.

So the question is: Is there any other possibilities to Zoom to extent of all features in the layer? May be I missed something in the API reference?

Najděte více příspěvků označených jako

Accepted answers

All comments

DominiqueBroux

How about just declaring one FeatureLayer and pass the url of your concerned layer (http://YourServer/ArcGIS/Rest/Services/ServiceName/MapSerer/layerIndex )to its constructor? Once it becomes the FeatureLayer, you can get its full extent.

You are right, that is a possible workaround, but you have to call by yourself the Initialize method of the FeatureLayer, then the layer infos will be available on event 'Layer.Initialized'.

SanajyJadhav

How about just declaring one FeatureLayer and pass the url of your concerned layer (http://YourServer/ArcGIS/Rest/Services/ServiceName/MapSerer/layerIndex )to its constructor? Once it becomes the FeatureLayer, you can get its full extent.

ChristopherHill

if you wanted to get at the json of the sublayer information from REST you would need to preform a web request. Here s an example of populating the sublayers into a list box and then requesting the sublayer json based on id. When the json response returns I look for the extent json, check its spatial reference to make sure it matches my maps spatial reference then preform a zoom to the sub layers extent. This example is just to demostrate how to get the infomation for the sublayer REST endpoints.

Xaml

<Grid x:Name="LayoutRoot" Background="White">        
        <Grid.Resources>
            <DataTemplate x:Key="ListBoxItem">
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <ColumnDefinition Width="*" />
                    </Grid.ColumnDefinitions>
                    <TextBlock Text="{Binding ID}" Margin="5,0" />
                    <TextBlock Text="{Binding Name}" Grid.Column="1" />
                </Grid>                                
            </DataTemplate>
        </Grid.Resources>
        <!--Map Control-->
        <esri:Map x:Name="esriMap">

            <!--Base Layer-->
            <esri:ArcGISTiledMapServiceLayer ID="baseLayer" 
                Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"/>

            <!--Dynamic Layer-->
            <esri:ArcGISDynamicMapServiceLayer ID="dynamicLayer" 
               Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/WaterTemplate/WaterDistributionAdministrativeReport/MapServer" 
               Initialized="ArcGISDynamicMapServiceLayer_Initialized"/>

        </esri:Map>
        
        <ListBox x:Name="SubLayersListBox" 
                 ItemTemplate="{StaticResource ListBoxItem}"
                 SelectionChanged="SubLayersListBox_SelectionChanged" 
                 VerticalAlignment="Top" 
                 HorizontalAlignment="Right" />
    </Grid>

Code Behind

ArcGISDynamicMapServiceLayer dynamicLayer;
  WebClient wc;
  SpatialReference WEB_MERCATOR = new SpatialReference(102100);
  SpatialReference GEOGRAPHIC = new SpatialReference(4326);
  WebMercator projection = new WebMercator();
  
  public MainPage()
  {
   InitializeComponent();
   wc = new WebClient();
   wc.DownloadStringCompleted += wc_DownloadStringCompleted;
  }

  private void ArcGISDynamicMapServiceLayer_Initialized(object sender, EventArgs e)
  {
   dynamicLayer = esriMap.Layers["dynamicLayer"] as ArcGISDynamicMapServiceLayer;
   List<LayerInfo> sublayers = new List<LayerInfo>();
   foreach (LayerInfo ld in dynamicLayer.Layers)
   {        
    sublayers.Add(ld);
   }

   SubLayersListBox.ItemsSource = sublayers;
  }
  

  private void SubLayersListBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
  {
   if (SubLayersListBox.SelectedIndex < 0) return;

   LayerInfo sublayerMetaData = SubLayersListBox.SelectedItem as LayerInfo;
   if (sublayerMetaData != null)
   {
    Uri uri = new Uri(string.Format("{0}/{1}?f=json",dynamicLayer.Url,sublayerMetaData.ID));
    if (wc.IsBusy)
     wc.CancelAsync();    

    if(!wc.IsBusy)
     wc.DownloadStringAsync(uri);
   }
  }

  void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
  {
   if (e.Error != null)
   {
    MessageBox.Show(e.Error.Message);
    return;
   }
   JsonValue jValue = JsonObject.Parse(e.Result);
   if (jValue.ContainsKey("extent"))
   {
    string sExtent = jValue["extent"].ToString();
    using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(sExtent)))
    {
     DataContractJsonSerializer ds = new DataContractJsonSerializer(typeof(Envelope));
     Envelope extent = ds.ReadObject(ms) as Envelope;

     if (!extent.SpatialReference.Equals(WEB_MERCATOR))
     {
      if (extent.SpatialReference.Equals(GEOGRAPHIC))
      {
       esriMap.ZoomTo(projection.FromGeographic(extent));
      }
      else
      {
       MessageBox.Show("Need to project spatial reference.");
      }
     }
     else
      esriMap.ZoomTo(extent);
    };
   }
   
  }

Assemblies
System.ServiceModel.Web <- DataContractSerializer
System.Json <- JsonValue

Namespaces

using System;
using System.Collections.Generic;
using System.IO;
using System.Json;
using System.Net;
using System.Runtime.Serialization.Json;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using ESRI.ArcGIS.Client;
using ESRI.ArcGIS.Client.Geometry;
using ESRI.ArcGIS.Client.Projection;

NickArnold

I have to clarify what I said in this thread because it could be confusing.

If your data are dynamic either because the data are loaded by other applications or because you are filtering at the client side (using layerdefs), it's not possible to easily know the extent at the client side (this was the initial subject of this thread).

Now if your data are static and that you can rely on the extent provided by the service, it's possible to get the extent of layer and sublayers at the client side:
- for a layer, there is a 'FullExtent' property
- for a sublayer, you can deserialize the info provided by the sublayer rest resource. For example, look at the extent info provided by this sublayer.

I'm not sure about doing this in Silverlight, but I had the exact same problem using the JSAPI and I solved it using an AJAX call to the server hosting the map services. (Caveat: This will only work if the map services are hosted on the same server as the web app.) Here's my code:

function zoomToLayer(id) {
        //first, try the layer.fullExtent property
 var layer = map.getLayer(id);
 if (layer != null) {
  map.setExtent(layer.fullExtent);
 }
 else {
  //the layer is a sublayer, so we must dig deeper
  dojo.forEach(map.layerIds, function(layerId) {
   layer = map.getLayer(layerId);
   dojo.forEach(layer.layerInfos, function(layerInfo) {
    if (layerInfo.name == id) {
     //now we have a match, so make an AJAX request to the server to get the
     //json description of this sublayer, which contains the extent 
     //so f'ing dumb that the LayerInfo object doesn't wrap this for us...
     var args = {
      url: "/arcgis/rest/services/Foo/Bar/MapServer/"+layerInfo.id,
      handleAs: "json",
      content: {f:"pjson"},
      load:function(data) {
       var extent = data.extent;
       var sr = data.extent.spatialReference;
       map.setExtent(new esri.geometry.Extent(extent.xmin,extent.ymin,extent.xmax,extent.ymax,sr));
      }
     };
     var deferred = dojo.xhrGet(args);
    }
   });
  });
 }
}

Problem solved. I'm sure there's a way to do this in Silverlight, but I literally have zero experience with it. I hope this saves someone some time.

DominiqueBroux

i also need to get into the sublayer of the service regardless of the effort needed .....

I have to clarify what I said in this thread because it could be confusing.

If your data are dynamic either because the data are loaded by other applications or because you are filtering at the client side (using layerdefs), it's not possible to easily know the extent at the client side (this was the initial subject of this thread).

Now if your data are static and that you can rely on the extent provided by the service, it's possible to get the extent of layer and sublayers at the client side:
- for a layer, there is a 'FullExtent' property
- for a sublayer, you can deserialize the info provided by the sublayer rest resource. For example, look at the extent info provided by this sublayer.

Hope this help.

priyajain

Dominique! Thank you for the confirmation...

Hi ,

i also need to get into the sublayer of the service regardless of the effort needed .....

if anybody knows pls help

thanks in advance
priya

AlexanderOvsyankin

I don't think it's possible if you are using MapServiceLayer.

You could either develop your own web service to calculate the extent or load the sublayer as FeatureLayer instead of MapServiceLayer (but there is a big cost specially if the only goal is to get the extent).

Dominique! Thank you for the confirmation...

DominiqueBroux

So I am interesting in functionality on how to zoom to particular sublayer in the service, not the service itself... Is it possible?

I don't think it's possible if you are using MapServiceLayer.

You could either develop your own web service to calculate the extent or load the sublayer as FeatureLayer instead of MapServiceLayer (but there is a big cost specially if the only goal is to get the extent).

AlexanderOvsyankin

Is this what you need or do you need?

[HTML]
        
        <esri:Map x:Name="esriMap">

            
            <esri:ArcGISTiledMapServiceLayer ID="baseLayer"
                Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"/>

            
            <esri:ArcGISDynamicMapServiceLayer ID="dynamicLayer"
               Url="..."
               Initialized="ArcGISDynamicMapServiceLayer_Initialized"/>

        </esri:Map>
[/HTML]
private void ArcGISDynamicMapServiceLayer_Initialized(object sender, EventArgs e)
{
   ArcGISDynamicMapServiceLayer dynamicLayer = esriMap.Layers["dynamicLayer"] as ArcGISDynamicMapServiceLayer;
   esriMap.Extent = dynamicLayer.FullExtent;
}

Thank you for the example, but again this example about service, not particular sublayer inside service...

So I am interesting in functionality on how to zoom to particular sublayer in the service, not the service itself... Is it possible?

ChristopherHill

Is this what you need or do you need?

[HTML]
        
        <esri:Map x:Name="esriMap">

            
            <esri:ArcGISTiledMapServiceLayer ID="baseLayer"
                Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer"/>

            
            <esri:ArcGISDynamicMapServiceLayer ID="dynamicLayer"
               Url="..."
               Initialized="ArcGISDynamicMapServiceLayer_Initialized"/>

        </esri:Map>
[/HTML]

private void ArcGISDynamicMapServiceLayer_Initialized(object sender, EventArgs e)
{
   ArcGISDynamicMapServiceLayer dynamicLayer = esriMap.Layers["dynamicLayer"] as ArcGISDynamicMapServiceLayer;
   esriMap.Extent = dynamicLayer.FullExtent;
}

AlexanderOvsyankin

What about this:
Map.Extent = yourLayer.FullExtent;
?

Thank you for your reply, but I have a question: when you are saying yourLayer.FullExtent under yourLayer you mean service? or separate layer in the particular service?

If you mean service then it is similar case to #1 of my initial post and it will zoom to full extent for the Data Frame that was set in mxd before publishing...

If you mean separate layer, could you, please, provide some portion of code how to get to this particular layer.FullExtent property?

egismazeika

What about this:
Map.Extent = yourLayer.FullExtent;
?

Připojte se k diskusi

Přihlášení členové mohou přispívat, sledovat aktualizace a další. Jste tu noví? Zaregistrujte si bezplatný účet.

Rychlé odkazy

Community Help
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.