private bool CreateLayeredWindowFromImgBuffer(IntPtr pImgBuffer, long cImgBufferLen, bool topMost)
{
bool bSuccess = false;
IntPtr pImagingFactory = IntPtr.Zero;
IntPtr pDecoder = IntPtr.Zero;
IntPtr pIStream = IntPtr.Zero;
IntPtr pDecodedFrame = IntPtr.Zero;
IntPtr pBitmapSourceFormatConverter = IntPtr.Zero;
IntPtr pBitmapFlipRotator = IntPtr.Zero;
try
{
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateImagingFactory(UnsafeNativeMethods.WIC.WINCODEC_SDK_VERSION, out pImagingFactory));
// Use the WIC stream class to wrap the unmanaged pointer
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateStream(pImagingFactory, out pIStream));
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.InitializeStreamFromMemory(pIStream, pImgBuffer, (uint)cImgBufferLen));
// Create an object that will decode the encoded image
Guid vendor = Guid.Empty;
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateDecoderFromStream(pImagingFactory, pIStream,
ref vendor, 0, out pDecoder));
// Get the frame from the decoder. Most image formats have only a single frame, in the case
// of animated gifs we are ok with only displaying the first frame of the animation.
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.GetFrame(pDecoder, 0, out pDecodedFrame));
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateFormatConverter(pImagingFactory, out pBitmapSourceFormatConverter));
// Convert the image from whatever format it is in to 32bpp premultiplied alpha BGRA
Guid pixelFormat = UnsafeNativeMethods.WIC.WICPixelFormat32bppPBGRA;
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.InitializeFormatConverter(pBitmapSourceFormatConverter, pDecodedFrame,
ref pixelFormat, 0 /*DitherTypeNone*/, IntPtr.Zero,
0, UnsafeNativeMethods.WIC.WICPaletteType.WICPaletteTypeCustom));
// Reorient the image
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateBitmapFlipRotator(pImagingFactory, out pBitmapFlipRotator));
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.InitializeBitmapFlipRotator(pBitmapFlipRotator, pBitmapSourceFormatConverter,
UnsafeNativeMethods.WIC.WICBitmapTransformOptions.WICBitmapTransformFlipVertical));
Int32 width, height;
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.GetBitmapSize(pBitmapFlipRotator, out width, out height));
Int32 stride = width * 4;
// initialize the bitmap header
MS.Win32.NativeMethods.BITMAPINFO bmInfo = new MS.Win32.NativeMethods.BITMAPINFO(width, height, 32 /*bpp*/);
bmInfo.bmiHeader_biCompression = MS.Win32.NativeMethods.BI_RGB;
bmInfo.bmiHeader_biSizeImage = (int)(stride * height);
// Create a 32bpp DIB. This DIB must have an alpha channel for UpdateLayeredWindow to succeed.
IntPtr pBitmapBits = IntPtr.Zero;
_hBitmap = UnsafeNativeMethods.CreateDIBSection(new HandleRef(), ref bmInfo, 0 /* DIB_RGB_COLORS*/, ref pBitmapBits, null, 0);
// Copy the decoded image to the new buffer which backs the HBITMAP
Int32Rect rect = new Int32Rect(0, 0, width, height);
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CopyPixels(pBitmapFlipRotator, ref rect, stride, stride * height, pBitmapBits));
_hwnd = CreateWindow(_hBitmap, width, height, topMost);
bSuccess = true;
}
finally
{
if (pImagingFactory != IntPtr.Zero)
{
Marshal.Release(pImagingFactory);
}
if (pDecoder != IntPtr.Zero)
{
Marshal.Release(pDecoder);
}
if (pIStream != IntPtr.Zero)
{
Marshal.Release(pIStream);
}
if (pDecodedFrame != IntPtr.Zero)
{
Marshal.Release(pDecodedFrame);
}
if (pBitmapSourceFormatConverter != IntPtr.Zero)
{
Marshal.Release(pBitmapSourceFormatConverter);
}
if (pBitmapFlipRotator != IntPtr.Zero)
{
Marshal.Release(pBitmapFlipRotator);
}
if (bSuccess == false)
{
DestroyResources(); // cleans up _hwnd and _hBitmap
}
}
return bSuccess;
}
private void DestroyResources()
{
if (_dt != null)
{
_dt.Stop();
_dt = null;
}
if (_hwnd != IntPtr.Zero)
{
HandleRef hwnd = new HandleRef(null, _hwnd);
if (UnsafeNativeMethods.IsWindow(hwnd))
{
UnsafeNativeMethods.IntDestroyWindow(hwnd);
}
_hwnd = IntPtr.Zero;
}
if (_hBitmap != null && !_hBitmap.IsClosed)
{
UnsafeNativeMethods.DeleteObject(_hBitmap.MakeHandleRef(null).Handle);
_hBitmap.Close();
_hBitmap = null;
}
if (_wndClass != 0)
{
// Attempt to unregister the window class. If the application has a second
// splash screen which is still open this call will fail. That's OK.
if (UnsafeNativeMethods.IntUnregisterClass(new IntPtr(_wndClass), _hInstance) != 0)
{
_defWndProc = null; // Can safely release the wndproc delegate when there are no more splash screen instances
}
_wndClass = 0;
}
if (_resourceManager != null)
{
_resourceManager.ReleaseAllResources();
}
}