Directx7 CreateSurfaceFromFile 的时候说找不见文件

[吴法吴天]

DxVBLib.DirectX7 dx = new DxVBLib.DirectX7();
DxVBLib.DirectDraw7 dDraw = dx.DirectDrawCreate("");
dDraw.SetCooperativeLevel(pnlPlay.Handle.ToInt32(),
DxVBLib.CONST_DDSCLFLAGS.DDSCL_NORMAL);
DxVBLib.RECT rect, rectSec;
DxVBLib.DDSURFACEDESC2 dDDesc = new DxVBLib.DDSURFACEDESC2();
DxVBLib.DirectDrawSurface7 dDsurface;
DxVBLib.DDSURFACEDESC2 dDDesc1 = new DxVBLib.DDSURFACEDESC2();
DxVBLib.DirectDrawSurface7 dDsurfaceSec;
dDDesc.lFlags = DxVBLib.CONST_DDSURFACEDESCFLAGS.DDSD_CAPS; dDDesc.ddsCaps.lCaps = DxVBLib.CONST_DDSURFACECAPSFLAGS.DDSCAPS_PRIMARYSURFACE;
dDsurface = dDraw.CreateSurface(ref dDDesc);
//dDsurfaceSec = dDraw.CreateSurfaceFromFile(sfile, ref dDDesc1);
dDsurfaceSec = dDraw.CreateSurfaceFromFile(@"e:\yuv2bmp_1.bmp", ref dDDesc1);

这个文件我确定存在。但是运行的时候总是在最后一行例外。说文件为找见