How to create a transparent bitmap in Direct2D
问题 I need to create a transparent bitmap using Direct2D and draw, by using my device context, on it. ID2D1DeviceContext1* d2dContext = ... ID2D1Bitmap* pBitmap; d2dContext->CreateBitmap( bitmapSize, nullptr, 0, D2D1::BitmapProperties1( D2D1_BITMAP_OPTIONS_TARGET, D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED), dpiX, dpiY), &pBitmap); d2dContext->BeginDraw(); d2dContext->SetTarget(pBitmap); d2dContext->Clear(D2D1::ColorF(0, 0)); d2dContext->DrawLine(...); hr =