vb&AE 怎么实现加载tif格式的栅格数据

<P>Public Sub AddRasterLayer(workspacePath As String, RasterName As String)</P>
<P>  Dim pWorkspaceFactory As IWorkspaceFactory<BR>  Dim pRasterWorkSpace As IRasterWorkspace<BR>  Dim pRSLayer As IRasterLayer<BR>  Dim pRasterDS As IRasterDataset</P>
<P>  On Error GoTo ErrorHandler:<BR>  <BR>  ' Create a factory object to generate workspace objects, then call the factory<BR>  ' with the supplied folder spec.<BR>  '<BR>  Set pWorkspaceFactory = New RasterWorkspaceFactory<BR>  Set pRasterWorkSpace = pWorkspaceFactory.OpenFromFile(workspacePath, hwnd)<BR>  <BR>  ' We now have a valid workspace,<BR>  ' within this workspace folder<BR>  <BR>  Set pRSLayer = New RasterLayer<BR>  Set pRasterDS = pRasterWorkSpace.OpenRasterDataset(RasterName)<BR>  pRSLayer.CreateFromDataset pRasterDS<BR>  MapControl1.AddLayer pRSLayer<BR>  Exit Sub</P>
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我的代码哪里错了  ？

各位大虾 帮帮忙  谢谢了!