topic Re: IdentifyTask and Multiple map services in ArcGIS API for Silverlight Questions

IdentifyTask and Multiple map services

AngelGonzalez — Thu, 17 Feb 2011 18:06:36 GMT

How would you go about using the IdentifyTasK with multiple map service? Sample code wouild be appreciate.

Re: IdentifyTask and Multiple map services

JenniferNery — Sun, 12 Dec 2021 04:25:31 GMT

You can refer and modify this sample: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#Identify

You can extend the scope of identifyTask by making it a private member of the class and subscribe to its ExecuteCompleted and Failed events upfront. You can also create a Stack or Queue of the map services Url.

identifyTask = new IdentifyTask();
identifyTask.ExecuteCompleted += IdentifyTask_ExecuteCompleted;
identifyTask.Failed += IdentifyTask_Failed;   
mapServices = new Stack<string>();
UpdateMapServices(); //TODO: push or enqueue map service URL's

In the MouseClick, you can simply update the Url property of IdentifyTask and then pass identifyParams as UserState to your IdentifyTask so you can re-use it for the other map services.

 identifyTask.Url = mapServices.Pop();
 identifyTask.ExecuteAsync(identifyParams, identifyParams);

In the ExecuteCompleted, you can call the succeeding Execute this way:

if (mapServices.Count == 0)
 UpdateMapServices(); //to re-add the map services for the next click event
else
{
 identifyTask.Url = mapServices.Pop();
 IdentifyParameters identifyParams = args.UserState as IdentifyParameters;
 identifyTask.ExecuteAsync(identifyParams, identifyParams );
}

Your task then is to update the UIElement. Notice that ShowFeatures() clears _dataItems and IdentifyComboBox so everytime new result comes back, the IdentifyResultGrid is cleared. You need to change this so that it can display results from all services.

Re: IdentifyTask and Multiple map services

DominiqueBroux — Sun, 20 Feb 2011 15:54:08 GMT

This code sample might also be useful http://www.arcgis.com/home/item.html?id=4a5af1f10e214a908ece9d18c01a2d25

Re: IdentifyTask and Multiple map services

AngelGonzalez — Wed, 23 Feb 2011 22:30:05 GMT

Jennifer & Dominique,

I used a combination of both codes to dynamically get my map services and populate the comboBox with the results.

Thanks for your help!

Re: IdentifyTask and Multiple map services

TobinCrain — Tue, 17 May 2011 19:32:15 GMT

angelg, can you expand on what you did to make this work?

Or Jennifer, can you help me out? I am also trying to identify from a dynamic service and a couple of tiled services. I could really use a little more detail in you explanation.

Thanks,
Tobin

Re: IdentifyTask and Multiple map services

TobinCrain — Mon, 23 May 2011 15:35:18 GMT

Thanks Angel. Your code sample really helped me out.

Re: IdentifyTask and Multiple map services

DanDong — Fri, 03 Jun 2011 02:11:01 GMT

Thank you guys!! This really offers me big help 😄

Re: IdentifyTask and Multiple map services

SantoshV — Sat, 06 Aug 2011 06:35:14 GMT

Hey thank you soo much for the code it was of great help..
However as we are using multiple services the the iteration is more as it iterates completely for every service.. is there a way where I can reduce the time taken for execute the complete program?

Re: IdentifyTask and Multiple map services

DominiqueBroux — Sat, 06 Aug 2011 10:13:25 GMT

In this sample, the identify tasks are executed in //.

You can test it with this web map.

Re: IdentifyTask and Multiple map services

SantoshV — Sun, 12 Dec 2021 04:25:37 GMT

Hi thanks for your reply..
I have gone through the sample but it is same as the above code as it also iterates through every service
My problem is that I have about 10 services running and iterating through 10 services takes more time so my identify tool works slow, populating the layername from the results into the combobox take a long time about2 seconds for each ltem

my code goes like this

private void QueryPoint_MouseClick(object sender, ESRI.ArcGIS.Client.Map.MouseEventArgs e)
{
           // create identifyParams object
            IdentifyParameters identifyParams = new IdentifyParameters()
            { 
                Geometry = mapPoint,
                //Tolerance = 50,
                MapExtent = mainPage.map.Extent,
                Width = (int)mainPage.map.ActualWidth,
                Height = (int)mainPage.map.ActualHeight,
                LayerOption = LayerOption.visible,
                SpatialReference = mainPage.map.SpatialReference
            };
            
            // store all the available services in to myMapService stack
            storeMapServices();
            identifyTask.Url = myMapService.Pop();
            identifyTask.ExecuteAsync(identifyParams, identifyParams);
  }

void identifyTask_ExecuteCompleted(object sender, IdentifyEventArgs e)
{
              if (e.IdentifyResults != null && e.IdentifyResults.Count > 0)
            {
                boolNeedReset = false;

                //get Layerkeyfield and add identify results to dictionary
                ShowFeatures(e.IdentifyResults);                
            }
            if (tempInt < 2)
            {
                identifyTask.Url = myMapService.Pop();      
                IdentifyParameters identifyParams = e.UserState as IdentifyParameters;
                identifyTask.ExecuteAsync(identifyParams, identifyParams);
            }
}

public void ShowFeatures(List<IdentifyResult> results)
        {
            int intFeatureCount = 0;

            //Get the Layer Key Field 
            
           DataAccessService.DataAccessServiceClient dataAccessServiceClient = new DataAccessService.DataAccessServiceClient();
           dataAccessServiceClient.getLayerKeyIDAsync(results[0].LayerName);
          dataAccessServiceClient.getLayerKeyIDCompleted += ((s, e) =>
           {
               if (e.Result != string.Empty && e.Result != null)
               {
                   kvpLayerKeyField.Add(results[0].LayerName, e.Result);
                   foreach (IdentifyResult result in results)
                   {
                       if (!kvpIdentifyResults.Keys.Contains(Convert.ToInt32(results[intFeatureCount].Feature.Attributes[e.Result])))
                       {
                           kvpIdentifyResults.Add(Convert.ToInt32(results[intFeatureCount].Feature.Attributes[e.Result]), results[intFeatureCount].LayerName);
                           intFeatureCount++;
                       }
                   }
                   //add identified layernames to combobox
                   IdentifyComboBox.Items.Add(results[0].LayerName);
               }
           }); 
}

Is there any other way to get mouse map pointer clicked element attributes form other then Identifytask?

Re: IdentifyTask and Multiple map services

DawnBlanchard — Tue, 16 Aug 2011 16:30:21 GMT

Hi,

Thanks for the code. I have a question. Where does the code set the IdentifyButtonClicked, IdentifyResultsPanelVisible, and _needReset? Would you please show the code behind the button?

Thanks in advance!

Re: IdentifyTask and Multiple map services

AngelGonzalez — Sun, 12 Dec 2021 04:25:39 GMT

Hi Dawn,
Below is the ButtonIdentify_Clicked code. By clicking on this button the IdentifyStackPanel will either be turned on or off as well as the initial setting of the IdentifyResultsPanel Visibility. The code I listed above will then update the status/value of the IdentifyResultsPanel & _needReset.

Hope this help

private void ButtonIdentify_Click(object sender, RoutedEventArgs e)
        {
            MyDrawObject.IsEnabled = false;
            if (IdentifyButtonClicked == false)
            {
                // Make IdentifyStackPAnel visible
                IdentifyButtonClicked = true;
                IdentifyStackPanel.Visibility = Visibility.Visible;
            }
            else
            {
                // Make IdentifyStackPanel not visibile, clear identify graphic, clear IdentifyComboBox & collapse
                IdentifyButtonClicked = false;
                IdentifyStackPanel.Visibility = Visibility.Collapsed;
                GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
                graphicsLayer.ClearGraphics();

                IdentifyComboBox.Items.Clear();
                IdentifyComboBox.UpdateLayout();

                IdentifyResultsPanel.Visibility = Visibility.Collapsed;

                MyMap.Cursor = Cursors.Arrow;
            }
        }

Re: IdentifyTask and Multiple map services

BarraLoubna — Wed, 20 Jun 2012 09:47:13 GMT

Hello, thank you very much for your suggetion

I tried what you suggested but it gives me a message errors like:
the name 'identifyTask_Failed' does not exist in the current context.
the name 'MapRow' does not exist in the current context.
the name 'e' does not exist in the current context.
....

On the other hand, I had managed to identify my attributes depending on the sample "query Identify" and use it:

IdentifyTask identifyTask IdentifyTask = new ("http://rom/ArcGIS/rest/services/.../MapServer");

I want when I click that button and I click on the map, the Identify window opens with the information of the attribute.

I managed to combine Identify a button in the toolbar that when I launch the   application, the Identify window does not opens, until I click the button, it appears, empty

code:
<esri1:ToolbarItem x:Name="Identify" Text="Identify">
<esri1:ToolbarItem.Content>
<Button >
   <Image Source="i_identify.png" Stretch="UniformToFill"/>
                                      <i:Interaction.Triggers>
                                          <i:EventTrigger EventName="Click">
                                              <local:ToggleVisibilityAction TargetName="IdentifyBorder">
                                              </local:ToggleVisibilityAction>
      </i:EventTrigger>
                                       </i:Interaction.Triggers>
                </Button>
</esri1:ToolbarItem.Content>
</esri1:ToolbarItem>

what I want is that when I click the button nothing appears until I click on the map, then the Identify window opens with the information ...

Re: IdentifyTask and Multiple map services

BarraLoubna — Thu, 28 Jun 2012 13:55:54 GMT

I return to post the solution I found,

for Identify an attribute after I selects the tools and I click on the map, I do:

bool test1 = false;

private void QueryPoint_MouseClick (object sender, ESRI.ArcGIS.Client.Map.MouseEventArgs e)
         {
....

if (test1)
    {

   IdentifyGrid.Visibility = Visibility.Visible;
   IdentifyBorder.Visibility = Visibility.Visible;
   IdentifyMap.Visibility = Visibility.Visible;
    }
}

and

private void Identify_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
   this.test1 = !this.test1;
   if (!test1)
    {

   IdentifyGrid.Visibility = Visibility.Collapsed;
   IdentifyBorder.Visibility = Visibility.Collapsed;
   IdentifyMap.Visibility = Visibility.Collapsed;
    }
}

Thank you.

Re: IdentifyTask and Multiple map services

AngelGonzalez — Sun, 12 Dec 2021 04:25:34 GMT

I basically started out with Identify on ESRI sample site, see second posting for link
On my site I have an Identify button that the user clicks to turn identify on and off. Using the code that Jennifer supplied I modified it as follows:

namespace SilverlightApplication1
{
    public partial class MainPage : UserControl
    {
        // Used by Identify
        private List<DataItem> _dataItems = null;
        bool IdentifyButtonClicked = false;
        private bool _needReset = true;                 //***
        bool IdentifyResultsPanelVisible = false;
        private IdentifyTask identifyTask = new IdentifyTask();
        public Stack<string> myMapService = new Stack<string>();
...

In the public MainPage I added the event handler:

public MainPage()
        {
            InitializeComponent();
            
            identifyTask.ExecuteCompleted +=new EventHandler<IdentifyEventArgs>(identifyTask_ExecuteCompleted);
            identifyTask.Failed +=new EventHandler<TaskFailedEventArgs>(identifyTask_Failed);

            UpdateMapServices();                //** This finds all dynamic map services I am using
        }

UpdateMapServices: Defines all dynamic map services that I am using

 //** Used by Identify 
        private void UpdateMapServices()
        {
            Stack<string> myTempStack = new Stack<string>();

            foreach (Layer layer in MyMap.Layers)
            {
                ArcGISDynamicMapServiceLayer dynamicLayer = layer as ArcGISDynamicMapServiceLayer;
                if (dynamicLayer != null)
                {
                    myTempStack.Push(dynamicLayer.Url.ToString());
                }
            }

            // Reverse stack order to reflect layers as drawn
            while (myTempStack.Count != 0)
            {
                myMapService.Push(myTempStack.Pop().ToString());
            }

        }

The MouseClick had been modified as follows:

 private void QueryPoint_MouseClick(object sender, Map.MouseEventArgs e)
        {

            if (IdentifyButtonClicked == true)   //*** Used by my IdentifyButton
            {
                if (IdentifyResultsPanelVisible)
                {
                    IdentifyResultsPanel.Visibility = Visibility.Collapsed;
                }

                MapPoint clickPoint = e.MapPoint;

                IdentifyParameters identifyParams = new IdentifyParameters()
                {
                    Geometry = clickPoint,
                    Tolerance = 20,
                    MapExtent = MyMap.Extent,
                    Width = (int)MyMap.ActualWidth,
                    Height = (int)MyMap.ActualHeight,
                    LayerOption = LayerOption.all,
                    SpatialReference = MyMap.SpatialReference
                };

                identifyTask.Url = myMapService.Pop();

                identifyTask.ExecuteAsync(identifyParams, identifyParams);

                MyMap.Cursor = Cursors.Wait;
               
                //  _needReset  is a flag used to determine if the user clicks on the map to a new  identify
                _needReset = true;              //***

                if (_needReset)                 //***
                {
                    GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
                    graphicsLayer.ClearGraphics();
                    ESRI.ArcGIS.Client.Graphic graphic = new ESRI.ArcGIS.Client.Graphic()
                    {
                        Geometry = clickPoint,
                        Symbol = MapRow.Resources["DefaultPictureSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol
                    };
                    graphicsLayer.Graphics.Add(graphic);
                }
            }

        }

Showfeature modified as follows:

public void ShowFeature(List<IdentifyResult> results)
        {
            // if true new identify is being requested, need to setup new list and clear identifyCombobox
            if (_needReset)                            {
                _dataItems = new List<DataItem>();
                IdentifyComboBox.Items.Clear();     //***
                _needReset = false;
            }
            
            if (results != null && results.Count > 0)
            {
                foreach (IdentifyResult result in results)
                {
                    Graphic feature = result.Feature;
                                                           
                    string tempLayerName = "(" + result.LayerName + ")";
                    
                    string title = tempLayerName.PadRight(20, ' ') +"|" + result.Value.ToString();// formatting
                    _dataItems.Add(new DataItem()
                    {
                        Title = title,
                        Data = feature.Attributes
                    });

                    IdentifyComboBox.Items.Add(title);
                }
                IdentifyComboBox.SelectedIndex = 0;
            }
        }

Once the IdentifyTask has been executed once(for the first dynamicMapService) you need to see if their is another dynamicMapservice

void identifyTask_ExecuteCompleted(object sender, IdentifyEventArgs e)
        {

            if (_needReset)           //If this is a new identify request then
            {
                IdentifyDetailDataGrid.ItemsSource = null;                  // clear datagrid
            }

            if (e.IdentifyResults != null && e.IdentifyResults.Count > 0)
            {
                ShowFeature(e.IdentifyResults);
            }
            else
            {
                IdentifyComboBox.Items.Clear();
                IdentifyComboBox.UpdateLayout();

                IdentifyResultsPanel.Visibility = Visibility.Collapsed;
                IdentifyResultsPanelVisible = false;
            }

            if (myMapService.Count == 0)                                 // once all map services had been identify then:
            {
                UpdateMapServices();                                        // re-populate the stack
                MyMap.Cursor = Cursors.Stylus;                              // set stylus
                IdentifyResultsPanel.Visibility = Visibility.Visible;       // show result panel
                IdentifyResultsPanelVisible = true;                         // set flag to true
            }
            else
            {
                identifyTask.Url = myMapService.Pop();                                      // get next dynamicMapService url for identify
                IdentifyParameters identifyParams = e.UserState as IdentifyParameters;      // pass in userstate
                identifyTask.ExecuteAsync(identifyParams, identifyParams);                  // execute 
            }

            

        }

The Identify Grid is put in a stackpanel

            <!--Identify-->
            <StackPanel x:Name="IdentifyStackPanel" Orientation="Vertical">
            <Border x:Name="IdentifyBorder" Background="#77919191" BorderThickness="1" CornerRadius="5"
                HorizontalAlignment="Left" BorderBrush="Gray"  VerticalAlignment="Top" Margin="5">
            <Border.Effect>
                <DropShadowEffect/>
            </Border.Effect>
            <Grid x:Name="IdentifyGrid" HorizontalAlignment="Right"  VerticalAlignment="Top" >
                <Grid.RowDefinitions>
                    <RowDefinition Height="30" />
                    <RowDefinition Height="*" />
                </Grid.RowDefinitions>
                <TextBlock x:Name="DataDisplayTitleBottom" Text="Click on map to Identify a feature"
                           Foreground="White" FontSize="10" Grid.Row="0"
                           Margin="15,5,15,1" HorizontalAlignment="Center" >
                    <TextBlock.Effect>
                        <DropShadowEffect />
                    </TextBlock.Effect>
                </TextBlock>
                <Grid x:Name="IdentifyResultsPanel" Margin="5,1,5,5" HorizontalAlignment="Center" 
                      VerticalAlignment="Top" Visibility="Collapsed" Grid.Row="1">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="30" />
                        <RowDefinition Height="*" />
                    </Grid.RowDefinitions>
                    <ComboBox x:Name="IdentifyComboBox" SelectionChanged="cb_SelectionChanged"
                              Margin="5,1,5,5" Grid.Row="0" FontFamily="Consolas" FontSize="12" Foreground="Brown">
                        
                    </ComboBox>
                    <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto"
                                  Width="330" MinHeight="200" Grid.Row="1">
                        <slData:DataGrid x:Name="IdentifyDetailDataGrid" AutoGenerateColumns="False" HeadersVisibility="None"
                                         Background="White">
                            <slData:DataGrid.Columns>
                                
                                <!--Shows field names*****-->
                                <slData:DataGridTextColumn Binding="{Binding Path=Key}" FontWeight="Bold"/>  
                                                                                                
                                <!--Shows field values*****-->
                                 <slData:DataGridTextColumn Binding="{Binding Path=Value}" />

                            </slData:DataGrid.Columns>
                        </slData:DataGrid>
                    </ScrollViewer>
                </Grid>
            </Grid>            
        </Border> 
        </StackPanel>

Hope this help