ListBox SelectionChanged zoom to index??

Question

Hi,

im having a problem with Zooming to a populated ListBox, i have a query that populates the Listbox and Zooms to the first object in the ListBox, but when i try to click on another object in the Box, nothing happens.

I used to have my SelectionChanged event to route back to my "QueryTask_ExecuteComplete" and that worked, but the problem with this was, that it added objects to my ListBox every time i clicked on an object in it, and if i tried to do a whole new Query, it crashed if i had clicked on an object in the ListBox.

this is my "QueryTask_ExecuteComplete":

void QueryTask_ExecuteCompleted(object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs args)
        {
            //query.Text = comboBox1.SelectedItem.ToString();
            FeatureSet featureSet = args.FeatureSet;

GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
            graphicsLayer.ClearGraphics();
                                 
            foreach (Graphic graphic in args.FeatureSet.Features)
                
                comboBox1.Items.Add(graphic.Attributes["Name"].ToString());

if (featureSet != null && featureSet.Features.Count > 0)
            {
                Graphic selectedfeature = featureSet.Features[0];
                //QueryDetailsDataGrid.ItemsSource = featureSet.Features;
                //QueryListbox.ItemsSource = featureSet.Features;

selectedfeature.Symbol = LayoutRoot.Resources["defaultFillSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
                graphicsLayer.Graphics.Add(selectedfeature);

ESRI.ArcGIS.Client.Geometry.Envelope selectedFeatureExtent = selectedfeature.Geometry.Extent;
                double expandPercentage = 30;

double widthExpand = selectedFeatureExtent.Width * (expandPercentage / 100);
                double heightExpand = selectedFeatureExtent.Height * (expandPercentage / 100);

ESRI.ArcGIS.Client.Geometry.Envelope displayExtent = new ESRI.ArcGIS.Client.Geometry.Envelope(
                selectedFeatureExtent.XMin - (widthExpand / 1),
                selectedFeatureExtent.YMin - (heightExpand / 1),
                selectedFeatureExtent.XMax + (widthExpand / 1),
                selectedFeatureExtent.YMax + (heightExpand / 1));

MyMap.ZoomTo(displayExtent);

}

THIS is my somewhat working SelectionChanged:

private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            //if (comboBox1.SelectedItem.ToString().Contains("Name"))
                //return;

QueryTask queryTask = new QueryTask("http://hkn082/ArcGIS/rest/services/Baskarta/Fastighetsytor/MapServer/2");
            queryTask.ExecuteCompleted += QueryTask_ExecuteCompleted;
            queryTask.Failed += QueryTask_Failed;

ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query();
            query.ReturnGeometry = true;
            //query.Text = comboBox1.SelectedItem.ToString();
            query.OutSpatialReference = MyMap.SpatialReference;
            //query.OutFields.Add("");

queryTask.ExecuteAsync(query);
        }

Any help would be helpful and appreciated

SanajyJadhav · Answer

Can you paste your code with point where code breaks here? Also, let me know the error message you are seeing.

BrianHjort_Nielsen · Answer

Hi again, and thanks!

I dont know if i am missing something or a reference, but i can't get the code to work, problems starts when i try to debug the code, what does your class header look like, my "querytask_executecompleted" is a "ESRI.ArcGIS.Client.Tasks.QueryEventArgs". and when i try out your code example i get the message that the arguments in your code cant be found in the class... =/

SanajyJadhav · Answer

.This is the class that saved the queried features. public class IdedFeatures { public string LayerName { get; set; } public IDictionary AttrData { get; set; } public string DisplayString { get; set; } public Graphic idedGraphic { get; set; } } Below should be your query completed event. if (e.IdentifyResults != null && e.IdentifyResults.Count > 0) { //List that will hold the all identified features as an instance our custom class "IdedFeatures" m_ListIdedFeatures = new List(); //loop thru each identified feature,create instance of the class "IdedFeatures", set its properties //using IdentifiedFeature and add this instance to its list. foreach (IdentifyResult idResult in e.IdentifyResults) { IdedFeatures idedFeat = new IdedFeatures(); idedFeat.LayerName = idResult.LayerName; idedFeat.AttrData = idResult.Feature.Attributes; idedFeat.idedGraphic = idResult.Feature; idedFeat.DisplayString = idResult.LayerName + " : " + idResult.Value; m_ListIdedFeatures.Add(idedFeat); } //set datasource of combo box cmbIdentifyResult.ItemsSource = null; cmbIdentifyResult.ItemsSource = m_ListIdedFeatures; } Below is the selection changed event of my Combo. Your's would be for the ListBox. //cast selected combo box item to the type of IdedFeatures so that we can have reference to the Graphic of the selected item. IdedFeatures selectedFeature = cmbIdentifyResult.SelectedItem as IdedFeatures; //zoom to the extent of the extent of the selected item in the listbox MapControl.Extent = selectedFeature.idedGraphic.Geometry.Extent; Let me know if this helps you. Thanks.