Performing map selection

About performing map selection

• SelectFeaturesScreenPoint - Selects features in the map based on a screen coordinate such as the coordinate obtained from a tool.
• SelectLayersFeatures - Selects features in a layer based on a Structured Query Language (SQL) WhereClause.
• SelectFeaturesPolygon - Performs a map selection based on a shape.
• ClearMapSelection - Clears the map selection.
• ClearLayerSelection - Clears a layer selection.

static void SelectFeaturesScreenPoint(IMap pMap, int x, int y, int pixelTol)
{
    tagRECT r;
    //Construct a small rectangle out of the x,y coordinates' pixel tolerance.
    r.left=x - pixelTol; //Upper left x, top left is 0,0.  
    r.top=y - pixelTol; //Upper left y, top left is 0,0.
    r.right=x + pixelTol; //Lower right x, top left is 0,0. 
    r.bottom=y + pixelTol; //Lower right y, top left is 0,0.

    //Transform the device rectangle into a geographic rectangle via the display transformation.  
    IEnvelope pEnvelope=new EnvelopeClass();
    IActiveView pActiveView=pMap as IActiveView;
    IDisplayTransformation pDisplayTrans =
        pActiveView.ScreenDisplay.DisplayTransformation;
    pDisplayTrans.TransformRect(pEnvelope, ref r, 5); 
        //5=esriTransformPosition + esriTransformToMap.

    pEnvelope.SpatialReference=pMap.SpatialReference;

    ISelectionEnvironment pSelectionEnvironment=new SelectionEnvironmentClass();
    pSelectionEnvironment.CombinationMethod =
        esriSelectionResultEnum.esriSelectionResultNew;
    pMap.SelectByShape(pEnvelope, pSelectionEnvironment, false);
}

static void SelectLayersFeatures(IFeatureLayer pFeatureLayer, string WhereClause)
{
    IFeatureSelection pFeatureSelection=pFeatureLayer as IFeatureSelection;
    if (pFeatureSelection != null)
    {
        IQueryFilter pQueryFilter=new QueryFilterClass();
        pQueryFilter.WhereClause=WhereClause;
        pFeatureSelection.SelectFeatures(pQueryFilter,
            esriSelectionResultEnum.esriSelectionResultNew, false);
    }
}

static void SelectFeaturesPolygon(IMap pMap, IPolygon pPolygon)
{
    ISelectionEnvironment pSelectionEnvironment=new SelectionEnvironmentClass();
    pSelectionEnvironment.CombinationMethod =
        esriSelectionResultEnum.esriSelectionResultNew;
    pMap.SelectByShape(pPolygon, pSelectionEnvironment, false);
}

static void ClearMapSelection(IMap pMap)
{
    pMap.ClearSelection();
}

static void ClearLayerSelection(IFeatureLayer pFeatureLayer)
{
    IFeatureSelection pFeatureSelection=pFeatureLayer as IFeatureSelection;
    if (pFeatureSelection != null)
    {
        pFeatureSelection.Clear();
    }
}

Shared Sub SelectFeaturesScreenPoint(ByVal pMap As IMap, ByVal x As Integer, ByVal y As Integer, ByVal pixelTol As Integer)
Dim r As tagRECT
'Construct a small rectangle out of the x,y coordinates' pixel tolerance.
r.Left=x - pixelTol 'Upper left x, top left is 0,0.
r.top=y - pixelTol 'Upper left y, top left is 0,0.
r.Right=x + pixelTol 'Lower right x, top left is 0,0.
r.bottom=y + pixelTol 'Lower right y, top left is 0,0.

'Transform the device rectangle into a geographic rectangle via the display transformation.
Dim pEnvelope As IEnvelope=New EnvelopeClass()
Dim pActiveView As IActiveView=pMap
Dim pDisplayTrans As IDisplayTransformation=pActiveView.ScreenDisplay.DisplayTransformation
pDisplayTrans.TransformRect(pEnvelope, r, 5) '5=esriTransformPosition + esriTransformToMap.

pEnvelope.SpatialReference=pMap.SpatialReference

Dim pSelectionEnvironment As ISelectionEnvironment=New SelectionEnvironmentClass()
pSelectionEnvironment.CombinationMethod=esriSelectionResultEnum.esriSelectionResultNew
pMap.SelectByShape(pEnvelope, pSelectionEnvironment, False)
End Sub

Shared Sub SelectLayersFeatures(ByVal pFeatureLayer As IFeatureLayer, ByVal WhereClause As String)
Dim pFeatureSelection As IFeatureSelection=pFeatureLayer
If Not pFeatureSelection Is Nothing Then
    Dim pQueryFilter As IQueryFilter=New QueryFilterClass()
    pQueryFilter.WhereClause=WhereClause
    pFeatureSelection.SelectFeatures(pQueryFilter, esriSelectionResultEnum.esriSelectionResultNew, False)
End If
End Sub

Shared Sub SelectFeaturesPolygon(ByVal pMap As IMap, ByVal pPolygon As IPolygon)
Dim pSelectionEnvironment As ISelectionEnvironment=New SelectionEnvironmentClass()
pSelectionEnvironment.CombinationMethod=esriSelectionResultEnum.esriSelectionResultNew
pMap.SelectByShape(pPolygon, pSelectionEnvironment, False)
End Sub

Shared Sub ClearMapSelection(ByVal pMap As IMap)
pMap.ClearSelection()
End Sub

Shared Sub ClearLayerSelection(ByVal pFeatureLayer As IFeatureLayer)
Dim pFeatureSelection As IFeatureSelection=pFeatureLayer
If Not pFeatureSelection Is Nothing Then
    pFeatureSelection.Clear()
End If
End Sub