Raster图层某点的value值的读取

<P>'IRasterLayer,pPoint 的接口很简单，这里不祥细介绍了</P>
<P>Function GetPixelValue(pRlayer As IRasterLayer, pPoint As IPoint) As String
Dim pBlockSize As IPnt
Set pBlockSize = New DblPnt
pBlockSize.SetCoords 1#, 1#</P>
<P>Dim pPixelBlock As IPixelBlock
Dim vValue As Variant
Dim i As Long, j As Long
Dim sPixelVals As String</P>
<P>sPixelVals = ""</P>
<P>Dim pRasterProps As IRasterProps
Dim dXSize As Double, dYSize As Double
Dim pPixel As IPnt
Set pPixel = New DblPnt</P>
<P>Set pPixelBlock = pRlayer.Raster.CreatePixelBlock(pBlockSize)</P>
<P>Set pRasterProps = pRlayer.Raster
dXSize = pRasterProps.Extent.XMax - pRasterProps.Extent.XMin
dYSize = pRasterProps.Extent.YMax - pRasterProps.Extent.YMin</P>
<P>dXSize = dXSize / pRasterProps.Width
dYSize = dYSize / pRasterProps.Height</P>
<P>pPixel.x = (pPoint.x - pRasterProps.Extent.XMin) / dXSize
pPixel.y = (pRasterProps.Extent.YMax - pPoint.y) / dYSize</P>
<P>pRlayer.Raster.Read pPixel, pPixelBlock
For j = 0 To pPixelBlock.Planes - 1</P>
<P>   vValue = pPixelBlock.GetVal(0, 0, 0)
   sPixelVals = sPixelVals ; Format(vValue, "##.0")
Next j
GetPixelValue = sPixelVals
End Function</P>

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