Public Function CreateBufferSelectionLayer( _
   ByVal filter As Filter, _
   ByVal selectionBuffer As SelectionBuffer, _
   ByVal selectionRenderer As Renderer, _
   ByVal newLayerID As String _
) As FeatureLayer

Visual Basic (Usage)	Copy Code
Dim instance As FeatureLayer Dim filter As Filter Dim selectionBuffer As SelectionBuffer Dim selectionRenderer As Renderer Dim newLayerID As String Dim value As FeatureLayer   value = instance.CreateBufferSelectionLayer(filter, selectionBuffer, selectionRenderer, newLayerID)

public FeatureLayer CreateBufferSelectionLayer( 
   Filter filter,
   SelectionBuffer selectionBuffer,
   Renderer selectionRenderer,
   string newLayerID
)

Parameters

filter

Filter of features to be buffered.

selectionBuffer

SelectionBuffer used to select features on the target layer.

selectionRenderer

Renderer used for the selected features.

newLayerID

ID of the created buffer selection layer.

Return Value

This example assumes an existing MapView object.

C#

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// Get a reference to the buffer source layer  //  -- we will construct a buffer around features in this layer  FeatureLayer originalLayer =      (FeatureLayer)mapView.Layers.FindByName("Rivers");     // Get a reference to the target layer   //  -- features in this layer will be highlighted  FeatureLayer targetLayer =       (FeatureLayer) mapView.Layers.FindByName("Cities");     // Create a filter and buffer to use with the the buffer layer  Filter layerFilter = new Filter("NAME = 'Mekong'");  SelectionBuffer selectionBuffer = new SelectionBuffer();  selectionBuffer.Distance = 100.0;  selectionBuffer.Units = BufferUnits.Kilometers;  selectionBuffer.WhereExpression = "POPULATION > 1000000";  selectionBuffer.TargetLayer = targetLayer;     // Create the renderer to display the selected features in the target layer  SimpleMarkerSymbol bufferSelSymbol =       new SimpleMarkerSymbol(System.Drawing.Color.Cyan,       16, MarkerSymbolType.Star);  SimpleRenderer bufferSelectionRenderer =       new SimpleRenderer(bufferSelSymbol);     // Create the buffer selection layer  FeatureLayer bufferSelectionLayer =      originalLayer.CreateBufferSelectionLayer(layerFilter,      selectionBuffer, bufferSelectionRenderer, "CitiesSelectedByBuffer");     // Add the buffer selection layer to the map  mapView.Layers.Add(bufferSelectionLayer);  Image1.ImageUrl = mapView.Draw().Url

Visual Basic

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' Get a reference to the buffer source layer ' -- will will construct a buffer around features in this layer Dim originalLayer As FeatureLayer = _     CType(mapView.Layers.FindByName("Rivers"), FeatureLayer) ' Get a reference to the target layer ' -- features in this layer will be highlighted Dim targetLayer As FeatureLayer = _     CType(mapView.Layers.FindByName("Cities"), FeatureLayer) ' Create a filter and buffer to use with the the buffer layer Dim layerFilter As New Filter("NAME = 'Mekong'") Dim selectionBuffer As New SelectionBuffer() selectionBuffer.Distance = 100.0 selectionBuffer.Units = BufferUnits.Kilometers selectionBuffer.WhereExpression = "POPULATION > 1000000" selectionBuffer.TargetLayer = targetLayer ' Create the renderer to display the selected features in the target layer Dim bufferSelSymbol As _     New SimpleMarkerSymbol(System.Drawing.Color.Cyan, _     16, MarkerSymbolType.Star) Dim bufferSelectionRenderer As _     New SimpleRenderer(bufferSelSymbol) ' Create the buffer selection layer Dim bufferSelectionLayer As FeatureLayer = _     originalLayer.CreateBufferSelectionLayer(layerFilter, _     selectionBuffer, bufferSelectionRenderer, "CitiesSelectedByBuffer") ' Add the buffer selection layer to the map mapView.Layers.Add(bufferSelectionLayer) Image1.ImageUrl = mapView.Draw().Url

This method selects and highlights features that fall within a buffer. The buffer is created by selecting features in the current feature layer using the filter parameter, and constructing a buffer around those features using the selectionBuffer parameter. The selection buffer object also specifies which layer to select from with the buffer. This layer is also known as the "target" layer for the buffer.

If you need to display the buffer itself, use CreateBufferLayer. A map can show both buffer and buffer selection layers. If you need to retrieve information about features found within a buffer, use Query(QueryParameters). If you need to select features by buffering around an arbitrary geometry object, use CreateSelectionLayer(Filter, Renderer, string), and set a Tolerance and Geometry for the Filter object.

Known limit: when using ArcMap Server image services, the FeatureLayer cannot be the same as the target layer for the buffer defined in SelectionBuffer.TargetLayer. If you need to buffer from and to the same data source, a workaround is to create two layers from the data source in the ArcMap document, and use the copy as the target layer.

The filter defines which features to buffer from. The buffer is drawn around these features. If no features are found with the filter, then no buffer will be created and therefore no features will be found and highlighted.

To display the features selected with the buffer, typically a SimpleRenderer is used for the renderer.

The buffer layer ID must be unique among all layers in the collection. The ID can be any combination of alpha and numeric characters.

If used with ArcMap image services, the layer's Renderer must be set to null before drawing the map. Renderers cannot be used in selection or buffer layers for ArcMap image services. If a renderer is used, an error will be thrown. As an alternative, use the FeatureLayer(FeatureLayer) to construct a copy of the layer, then set the Filter, Buffer and ID of the new layer before adding it to the map's layer collection.

Reference