Unmanaged Memory leak

Question

I have am using a WPF application which uses BitmapSource but I need to do some manipulation but I need to do some manipulation of System.Drawing.Bitmaps.

The memory use of the application increases while it runs.

I have narrowed down the memory leak to this code:

private BitmapSource BitmaptoBitmapsource(System.Drawing.Bitmap bitmap)
{
            BitmapSource bms;
            IntPtr hBitmap = bitmap.GetHbitmap();
            BitmapSizeOptions sizeOptions = BitmapSizeOptions.FromEmptyOptions();
            bms = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, sizeOptions);
            bms.Freeze();
            return bms;
}

I assume it is the unmanaged memory not being disposed of properly, but I cannot seem to find anyway of doing it manually. Thanks in advance for any help!

Alex

Answer 1

You need to call DeleteObject(...) on your hBitmap. See: http://msdn.microsoft.com/en-us/library/1dz311e4.aspx

private BitmapSource BitmaptoBitmapsource(System.Drawing.Bitmap bitmap)
{
    BitmapSource bms;
    IntPtr hBitmap = bitmap.GetHbitmap();
    BitmapSizeOptions sizeOptions = BitmapSizeOptions.FromEmptyOptions();
    bms = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, 
        IntPtr.Zero, Int32Rect.Empty, sizeOptions);
    bms.Freeze();

    // NEW:
    DeleteObject(hBitmap);

    return bms;
}

Answer 2

You need to call DeleteObject(hBitmap) on the hBitmap:

private BitmapSource BitmaptoBitmapsource(System.Drawing.Bitmap bitmap) {
        BitmapSource bms;
        IntPtr hBitmap = bitmap.GetHbitmap();
        BitmapSizeOptions sizeOptions = BitmapSizeOptions.FromEmptyOptions();
        try {
            bms = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, sizeOptions);
            bms.Freeze();
        } finally {
            DeleteObject(hBitmap);
        }
        return bms;
}