Buffer Distance

JayKappy · ‎01-25-2011

I have a buffer working off of a Query.
A query runs finding a Parcel
That selected feature then is used to run a buffer that selects another set of Feature within that buffer
It then returns them to a listbox

NOTE: everything works great...Just trying to figure out how if I can retrieve the distance each feature is to the buffer centerpoint.

How do I return the Buffer distance for each feature and put the distance in the listbox.
Is there something that I can do in the xaml below, or do I have to get the value in the vb code first?
Once that is gotten can I sort the values in the listbox Ascending via this buffer distance?

<TextBlock Foreground="White" Margin="0,4,0,0" VerticalAlignment="Center" Text="{Binding BUFFER_DISTANCE}" SORT="ASCENDING" />

Is this even possible with the Buffer? I assume that its measuring the distance in order to determine if its inside the Buffer specified distance.....

Thanks

<ListBox.ItemTemplate>
     <DataTemplate>
           <StackPanel Orientation="Horizontal" VerticalAlignment="Center" >
                    <!-- QUERY -->
                    <StackPanel Margin="1">
                            <TextBlock Foreground="White" Margin="0,4,0,0" VerticalAlignment="Center" Text="{Binding Attributes[TYPE]}"/>
                     </StackPanel>
                     <StackPanel Margin="5,0,0,0" Orientation="Vertical">
                             <TextBlock Foreground="White" Text="{Binding Attributes[CITY_NAME], StringFormat='City Name: \{0\}'}" >
                                      <TextBlock.Effect>
                                              <DropShadowEffect/>
                                      </TextBlock.Effect>
                             </TextBlock>
                             <TextBlock Foreground="White" Text="{Binding Attributes[POP1990], StringFormat='Population: \{0\}'}"  >
                                      <TextBlock.Effect>
                                              <DropShadowEffect/>
                                      </TextBlock.Effect>
                             </TextBlock>
                        </StackPanel>
                    </StackPanel>
              </DataTemplate>
       </ListBox.ItemTemplate>
</ListBox>

JenniferNery · ‎01-25-2011

This Text="{Binding BUFFER_DISTANCE}" will work if you add graphic Attribute with Key 'BUFFER_DISTANCE.' Yes, this need to be added in code-behind.

You can iterate through the graphics in your GraphicsLayer and calculate the Eucledian distance between buffer point and graphic.Geometry.Extent.GetCenter() and store into the graphic Attribute.

For Each g As var In MyGraphicsLayer.Graphics
 Dim c As MapPoint = g.Geometry.Extent.GetCenter()
 g.Attribute("BUFFER_DISTANCE") = GetDistance(bufferPoint, c)
Next

There is no Sort property on TextBox. If you wish to sort the ListBox contents against this Attribute, you can sort using Linq before setting ItemSource or use CollectionViewSource.

JayKappy · ‎01-26-2011

What you are saying makes sense.....I think my application is a bit different...

The user clicks a button that does a search on a value from a textblock.
The Parcel is located adn zoomed to
A buffer is created from that found parcel geometry
The buffer then selects the points within that buffer and returns the results to a listbox.

I am not seeing the location to place the code to calculate the Buffer Distance

            ' DRAW THE BUFFER AND USE THE PARCEL TO CREATE THE INITIAL POINT OF THE BUFFER
            _geometryService = New GeometryService("http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer")
            AddHandler _geometryService.BufferCompleted, AddressOf GeometryService_BufferCompleted2
            AddHandler _geometryService.Failed, AddressOf GeometryService_Failed2

            _queryTask = New QueryTask("http://gis.logis.org/arcgis/rest/services/MG_Test_WGS84/MapServer/1")
            AddHandler _queryTask.ExecuteCompleted, AddressOf QueryTask_ExecuteCompletedBuffer2
            AddHandler _queryTask.Failed, AddressOf QueryTask_Failed2

It seems I would put it here:
For Each selectedGraphic As Graphic In args.FeatureSet.Features
selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
_resultsGraphicsLayer.Graphics.Add(selectedGraphic)
Next selectedGraphic

But then I get confused because I am binding the imagelistbuffer (listbox) here
imageListBuffer.ItemsSource = args.FeatureSet.Features

    Private Sub GeometryService_BufferCompleted2(ByVal sender As Object, ByVal args As GraphicsEventArgs)
        Dim bufferGraphic As New Graphic()
        bufferGraphic.Geometry = args.Results(0).Geometry
        bufferGraphic.Symbol = TryCast(LayoutRoot.Resources("BufferSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
        bufferGraphic.SetZIndex(1)

        _pointAndBufferGraphicsLayer.Graphics.Add(bufferGraphic)

        Dim query As New ESRI.ArcGIS.Client.Tasks.Query()
        query.ReturnGeometry = True
        query.OutSpatialReference = MyMap.SpatialReference
        query.Geometry = bufferGraphic.Geometry
        query.OutFields.Add("*")
        _queryTask.ExecuteAsync(query)
    End Sub


    Private Sub QueryTask_ExecuteCompletedBuffer2(ByVal sender As Object, ByVal args As QueryEventArgs)

         ' Bind the results to the listbox
        Dim featureSet As FeatureSet = args.FeatureSet
        imageListBuffer.ItemsSource = args.FeatureSet.Features

        If args.FeatureSet.Features.Count < 1 Then
            MessageBox.Show("No features found")
            Return
        End If
        For Each selectedGraphic As Graphic In args.FeatureSet.Features
            selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            _resultsGraphicsLayer.Graphics.Add(selectedGraphic)
        Next selectedGraphic
    End Sub

JayKappy · ‎01-26-2011

I tried this but nothing going on the: GetDistance(bufferPoint,c)

    Private Sub QueryTask_ExecuteCompletedBuffer2(ByVal sender As Object, ByVal args As QueryEventArgs)

        Dim graphicsLayer As GraphicsLayer = TryCast(MyMap.Layers("MyGraphicsLayerBufferResults"), GraphicsLayer)

        For Each g As Graphic In graphicsLayer.Graphics
            Dim c As MapPoint = g.Geometry.Extent.GetCenter()
            g.Attributes("BUFFER_DISTANCE") = GetDistance(bufferPoint, c)
        Next

        Dim featureSet As FeatureSet = args.FeatureSet
        imageListBuffer.ItemsSource = args.FeatureSet.Features

        If args.FeatureSet.Features.Count < 1 Then
            MessageBox.Show("No features found")
            Return
        End If
        For Each selectedGraphic As Graphic In args.FeatureSet.Features
            selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            _resultsGraphicsLayer.Graphics.Add(selectedGraphic)

        Next selectedGraphic

    End Sub

dotMorten_esri · ‎01-26-2011

Isn't it the args.FeatureSet.Features that you want to add the attribute to, and not the graphics layer? (since this is what you bind to the listbox).

JayKappy · ‎01-27-2011

I tried this as well just didnt put it in the forum...
I am having a problem I think because the params on the Sub are args As QueryEvent and geometry is not a member of ESRI Tasks.QueryEventArgs
So I cant see how to get teh geometry from the center of each feature

Do I need to do this in a different method or change the Sub Params?
This the only sub tht I can think of placing this data as this is where i am binding the results to the listbox..


    Private Sub QueryTask_ExecuteCompletedBuffer2(ByVal sender As Object, ByVal args As QueryEventArgs)
        Dim featureSet As FeatureSet = args.FeatureSet
        imageListBuffer.ItemsSource = args.FeatureSet.Features

        If args.FeatureSet.Features.Count < 1 Then
            MessageBox.Show("No features found")
            Return
        End If
        For Each selectedGraphic As Graphic In args.FeatureSet.Features
            selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            _resultsGraphicsLayer.Graphics.Add(selectedGraphic)

            Dim c As MapPoint = args.Geometry.Extent.GetCenter()
            args.Attributes("BUFFER_DISTANCE") = GetDistance(bufferPoint, c)

        Next selectedGraphic

Then tried this: But the GetDistance errors out saying that GetDistance and bufferPoint are not declared...

        For Each selectedGraphic As Graphic In args.FeatureSet.Features
            selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            _resultsGraphicsLayer.Graphics.Add(selectedGraphic)

            Dim c As MapPoint = selectedGraphic.Geometry.Extent.GetCenter()
            selectedGraphic.Attributes("BUFFER_DISTANCE") = GetDistance(bufferPoint, c)

        Next selectedGraphic

.I cannot see the solution here..anyone? THanks

uggggggggggggggggggggg

JayKappy · ‎01-27-2011

Am I wasting my time by doing this here in the ... if I am even tryign this in the righ location....or even trying to do it correctly

Private Sub QueryTask_ExecuteCompletedBuffer2(ByVal sender As Object, ByVal args As QueryEventArgs)

It seems that GetDistance is not an option

JayKappy · ‎01-28-2011

I tried this as well....adding
ESRI.ArcGIS.Client.Geometry.MapPoint

instead of just MapPoint...keeps telling me that GetDistance and bufferPoint not defined.

    Private Sub QueryTask_ExecuteCompletedBuffer2(ByVal sender As Object, ByVal args As QueryEventArgs)

        Dim featureSet As FeatureSet = args.FeatureSet
        imageListBuffer.ItemsSource = args.FeatureSet.Features

        If args.FeatureSet.Features.Count < 1 Then
            MessageBox.Show("No features found")
            Return
        End If
        For Each selectedGraphic As Graphic In args.FeatureSet.Features
            selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            _resultsGraphicsLayer.Graphics.Add(selectedGraphic)

            Dim c As ESRI.ArcGIS.Client.Geometry.MapPoint = selectedGraphic.Geometry.Extent.GetCenter()
            selectedGraphic.Attributes("BUFFER_DISTANCE") = GetDistance(bufferPoint, c)
        Next selectedGraphic

    End Sub

Is GetDistance supposed to be a function that I am passing 'c' to in order find the distance?
Seems the way I have things set up it cant find the Buffer Point???? only the c (the parcel center point) is defined.
The center point of the buffer was defined in an ealier sub routine...

JayKappy · ‎01-31-2011

I take it I hit my question limit....wish I had another location to ask questions....I know that I am close here...thanks anyway...although still open for help

JayKappy · ‎01-31-2011

Io think that I can get the Buffer Graphics center like this: See RED below, BUT its not in the correct Sub Routine...
I need to get that center location to the Private Sub QueryTask_ExecuteCompletedBuffer2 in order to calculate the Distance from the Buffer center to the features found inside the buffer.

    Private Sub GeometryService_BufferCompleted2(ByVal sender As Object, ByVal args As GraphicsEventArgs)
        Dim bufferGraphic As New Graphic()
        bufferGraphic.Geometry = args.Results(0).Geometry
        bufferGraphic.Symbol = TryCast(LayoutRoot.Resources("BufferSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
        bufferGraphic.SetZIndex(1)

        _pointAndBufferGraphicsLayer.Graphics.Add(bufferGraphic)

        Dim bp As ESRI.ArcGIS.Client.Geometry.MapPoint = bufferGraphic.Geometry.Extent.GetCenter()        

        Dim query As New ESRI.ArcGIS.Client.Tasks.Query()
        query.ReturnGeometry = True
        query.OutSpatialReference = MyMap.SpatialReference
        query.Geometry = bufferGraphic.Geometry
        query.OutFields.Add("*")
        _queryTask.ExecuteAsync(query)
    End Sub

    Private Sub QueryTask_ExecuteCompletedBuffer2(ByVal sender As Object, ByVal args As QueryEventArgs)

        Dim featureSet As FeatureSet = args.FeatureSet
        imageListBuffer.ItemsSource = args.FeatureSet.Features

        If args.FeatureSet.Features.Count < 1 Then
            MessageBox.Show("No features found")
            Return
        End If
        For Each selectedGraphic As Graphic In args.FeatureSet.Features
            selectedGraphic.Symbol = TryCast(LayoutRoot.Resources("DefaultMarkerSymbol"), ESRI.ArcGIS.Client.Symbols.Symbol)
            _resultsGraphicsLayer.Graphics.Add(selectedGraphic)

            Dim c As ESRI.ArcGIS.Client.Geometry.MapPoint = selectedGraphic.Geometry.Extent.GetCenter()
            selectedGraphic.Attributes("BUFFER_DISTANCE") = GetDistance(bp, c)

        Next selectedGraphic

    End Sub