问题
I have an existing component that draws Direct2D content to an ID2D1RenderTarget and I would like to save that drawing to an image file. The questions here, here and here, although they helped me, did not provide a clear answer as how to do it.
My nullth idea was to try the official MSDN method. Unfortunately, it is not available in Win7.
My first idea was to modify the drawing routine to make it accept the RenderTarget as a parameter and use ID2D1Factory::CreateWicBitmapRenderTarget to draw directly into a IWICBitmap, but it turns out to be quite difficult for me (because it would be necessary to modify not only the drawing routine itself, but also the drawing callbacks of all users of that component (the code, written in Delphi, uses Embarcadero's TDirect2DCanvas, and thus did not need to manage all Direct2D resources, like render target or brushes)).
My second idea was to create an ID2D1Bitmap, fill it with what is already drawn using ID2D1Bitmap::CopyFromRenderTarget and then draw that ID2D1Bitmap to a WicBitmapRenderTarget (this is about what was done here). I had the same kind of problems as those who asked the questions I link to: different resources affinities, as briefly explained Kenny Kerr.
So is it possible under Win7 without having to implement my first idea, and how would you do it?
回答1:
Direct2D 1.1 is supported on Windows 7 if you install the Platform Update. Unfortunately, that doesn't solve your problem without first creating two more of them: 1) it's still pre-release/beta, and 2) it adds another installation dependency for you to worry about.
来源：https://stackoverflow.com/questions/14689806/how-to-save-the-content-of-a-id2d1rendertarget-to-a-file