如何进行空间查询

本例实现的是在一个图层上画一个polygon，根据该polygon查询出图层上与之相交的polygon并高亮显示出来。

要点

通过RubberPolygon类来实现接口IRubberBand接口对象，用IRubberBand.TrackNew方法在图层上画出polygon,然后定义IGeometry获得该polygon,创建ISpatialFilter接口对象实现过滤功能，通过ILayer接口实例获得IFeatureSelection接口，调用IFeatureSelection.SelectFeatures方法将结果高亮显示。

程序说明

过程UIToolControl1_MouseDown是实现模块。

代码

Option Explicit

Private Function UIToolControl1_Deactivate() As Boolean

UIToolControl1_Deactivate = True

End Function

Private Sub UIToolControl1_MouseDown(ByVal button As Long, ByVal shift As Long, _

ByVal x As Long, ByVal y As Long)

Dim pMxDoc As IMxDocument

Dim pActiveView As IActiveView

Dim pScreenDisplay As IScreenDisplay

Dim pRubberPolygon As IRubberBand

Dim pFillSymbol As ISimpleFillSymbol

Dim pRgbColor As IRgbColor

Dim pPolygon As IPolygon

Dim pGeometry As IGeometry

Dim pFeatselect As IFeatureSelection

Dim pSpatialFilter As ISpatialFilter

On Error GoTo ErrorHandler:

Set pMxDoc = ThisDocument

Set pActiveView = pMxDoc.FocusMap

'Draw Polygon

Set pScreenDisplay = pActiveView.ScreenDisplay

Set pRubberPolygon = New RubberPolygon

Set pFillSymbol = New SimpleFillSymbol

Set pRgbColor = New RgbColor

pRgbColor.NullColor = True

pFillSymbol.Color = pRgbColor

Set pPolygon = pRubberPolygon.TrackNew(pScreenDisplay, pFillSymbol)

With pScreenDisplay

.StartDrawing pScreenDisplay.hDC, esriNoScreenCache

.SetSymbol pFillSymbol

.DrawPolygon pPolygon

.FinishDrawing

End With

'set up pFilter

Set pGeometry = pPolygon

Set pSpatialFilter = New SpatialFilter

With pSpatialFilter

Set .Geometry = pGeometry

.SpatialRel = esriSpatialRelIntersects

End With

'select

Set pFeatselect = pMxDoc.FocusMap.Layer(0)

pFeatselect.SelectFeatures pSpatialFilter, esriSelectionResultNew, False

pFeatselect.SelectionSet.**

pMxDoc.ActiveView.**

Exit Sub

ErrorHandler:

MsgBox Err.Description

End Sub