[求助]OpenDialog 打开ESRI GRID数据？

<P>我想利用OpenDialog打开ESRI GRID文件，却实现不了？请教大虾帮助。c#+ae代码如下：</P>
<P>OpenFileDialog filedlg_addraster = new OpenFileDialog();<BR>filedlg_addraster.Filter = "ESRI GRID|<GRID>|All Files|*.*";<BR>if (filedlg_addraster.ShowDialog() == DialogResult.OK)<BR>            {<BR>                string m_FileName = Path.GetFileName(filedlg_addraster.FileName);<BR>                string m_FilePath = Path.GetDirectoryName(filedlg_addraster.FileName);<BR>                IWorkspaceFactory iWsFactory = new RasterWorkspaceFactoryClass();<BR>                IRasterWorkspace iRasWs;<BR>                if(iWsFactory.IsWorkspace(m_FilePath))<BR>                {<BR>                    iRasWs = (IRasterWorkspace)iWsFactory.OpenFromFile(m_FilePath, 0);<BR>                    IRasterDataset iRasDs = iRasWs.OpenRasterDataset(m_FileName);                <BR>                    IRasterLayer iRLayer = new RasterLayerClass();                    <BR>                    iRLayer.CreateFromDataset(iRasDs);<BR>                    ILayer iLayer = iRLayer;<BR>                    axMapControl1.AddLayer(iLayer, 0);<BR>                }</P>

<P  align=left>void  AddRasterLayer(IMap map, IRasterDataset rasterDataset)<p></p></P>
<P  align=left>{<p></p></P>
<P  align=left>  // rasterDataset represents a RasterDataset from raster workspace, access workspace or sde workspace.<p></p></P>
<P  align=left>  // map represents the Map to add the layer to once it is created<p></p></P>
<P  align=left>       <p></p></P>
<P  align=left>  // Create a raster layer. Use CreateFromRaster method when creating from a Raster.<p></p></P>
<P  align=left>  IRasterLayer rasterLayer = new RasterLayerClass();<p></p></P>
<P  align=left>  rasterLayer.CreateFromDataset(rasterDataset);<p></p></P>
<P  align=left><p> </p></P>
<P  align=left>  // Add the raster layer to Map <p></p></P>
<P  align=left>  map.AddLayer(rasterLayer);<p></p></P>
<P  align=left><p> </p></P>
<P  align=left>  // QI for availabilty of the IActiveView interface for a screen update<p></p></P>
<P  align=left>  IActiveView activeView = map as IActiveView;<p></p></P>
<P  align=left><p> </p></P>
<P  align=left>  if (activeView != null) <p></p></P>
<P  align=left>    activeView.Refresh();<p></p></P>
<P  align=left>}<p></p></P>

大虾，我用OpenDialog打开时，就不能像ArcMap那样显示出GRID文件，怎样解决？而ArcEngine又不能用GxDialog，求大虾们指教！

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