[ACCEPTED]-WPF CreateBitmapSourceFromHBitmap() memory leak-memory-leaks

MSDN for Bitmap.GetHbitmap() states:

Remarks

You are responsible for calling 4 the GDI DeleteObject method to free the 3 memory used by the GDI bitmap object.

So 2 use the following code:

// at class level
[System.Runtime.InteropServices.DllImport("gdi32.dll")]
public static extern bool DeleteObject(IntPtr hObject);

// your code
using (System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(1000, 1000)) 
{
    IntPtr hBitmap = bmp.GetHbitmap(); 

    try 
    {
        var source = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
    }
    finally 
    {
        DeleteObject(hBitmap);
    }
}

I also replaced your 1 Dispose() call by an using statement.

Whenever dealing with unmanaged handles 8 it can be a good idea to use the "safe handle" wrappers:

public class SafeHBitmapHandle : SafeHandleZeroOrMinusOneIsInvalid
{
    [SecurityCritical]
    public SafeHBitmapHandle(IntPtr preexistingHandle, bool ownsHandle)
        : base(ownsHandle)
    {
        SetHandle(preexistingHandle);
    }

    protected override bool ReleaseHandle()
    {
        return GdiNative.DeleteObject(handle) > 0;
    }
}

Construct 7 one like so as soon as you surface a handle 6 (ideally your APIs would never expose IntPtr, they 5 would always return safe handles):

IntPtr hbitmap = bitmap.GetHbitmap();
var handle = new SafeHBitmapHandle(hbitmap , true);

And use 4 it like so:

using (handle)
{
  ... Imaging.CreateBitmapSourceFromHBitmap(handle.DangerousGetHandle(), ...)
}

The SafeHandle base gives you 3 an automatic disposable/finalizer pattern, all 2 you need to do is override the ReleaseHandle 1 method.

I had the same requirement and issue (memory 12 leak). I implemented the same solution as 11 marked as answer. But although the solution 10 works, it caused an unacceptable hit to 9 performance. Running on a i7, my test app 8 saw a steady 30-40% CPU, 200-400MB RAM increases 7 and the garbage collector was running almost 6 every millisecond.

Since I'm doing video 5 processing, I'm in need of much better performance. I 4 came up with the following, so thought I 3 would share.

Reusable Global Objects

//set up your Bitmap and WritableBitmap as you see fit
Bitmap colorBitmap = new Bitmap(..);
WriteableBitmap colorWB = new WriteableBitmap(..);

//choose appropriate bytes as per your pixel format, I'll cheat here an just pick 4
int bytesPerPixel = 4;

//rectangles will be used to identify what bits change
Rectangle colorBitmapRectangle = new Rectangle(0, 0, colorBitmap.Width, colorBitmap.Height);
Int32Rect colorBitmapInt32Rect = new Int32Rect(0, 0, colorWB.PixelWidth, colorWB.PixelHeight);

Conversion Code

private void ConvertBitmapToWritableBitmap()
{
    BitmapData data = colorBitmap.LockBits(colorBitmapRectangle, ImageLockMode.WriteOnly, colorBitmap.PixelFormat);

    colorWB.WritePixels(colorBitmapInt32Rect, data.Scan0, data.Width * data.Height * bytesPerPixel, data.Stride);

    colorBitmap.UnlockBits(data); 
}

Implementation Example

//do stuff to your bitmap
ConvertBitmapToWritableBitmap();
Image.Source = colorWB;

The result is a steady 10-13% CPU, 70-150MB 2 RAM, and the garbage collector only ran 1 twice in a 6 minute run.

This is a great(!!) post, although with 11 all the comments and suggestions, it took 10 me an hour to figure out the pieces. So 9 here is a call to get the BitMapSource with 8 SafeHandles, and then an example usage of 7 it to create a .PNG image file. At the very 6 bottom are the 'usings' and some of the 5 references. Of course, none of the credit 4 is mine, I am just the scribe.

private static BitmapSource CopyScreen()
{
    var left = Screen.AllScreens.Min(screen => screen.Bounds.X);
    var top = Screen.AllScreens.Min(screen => screen.Bounds.Y);
    var right = Screen.AllScreens.Max(screen => screen.Bounds.X + screen.Bounds.Width);
    var bottom = Screen.AllScreens.Max(screen => screen.Bounds.Y + screen.Bounds.Height);
    var width = right - left;
    var height = bottom - top;

    using (var screenBmp = new Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
    {
        BitmapSource bms = null;

        using (var bmpGraphics = Graphics.FromImage(screenBmp))
        {
            IntPtr hBitmap = new IntPtr();
            var handleBitmap = new SafeHBitmapHandle(hBitmap, true);

            try
            {
                bmpGraphics.CopyFromScreen(left, top, 0, 0, new System.Drawing.Size(width, height));

                hBitmap = screenBmp.GetHbitmap();

                using (handleBitmap)
                {
                    bms = Imaging.CreateBitmapSourceFromHBitmap(
                        hBitmap,
                        IntPtr.Zero,
                        Int32Rect.Empty,
                        BitmapSizeOptions.FromEmptyOptions());

                } // using

                return bms;
            }
            catch (Exception ex)
            {
                throw new ApplicationException($"Cannot CopyFromScreen. Err={ex}");
            }

        } // using bmpGraphics
    }   // using screen bitmap
} // method CopyScreen

Here is the 3 usage, and also the "Safe Handle" class:

private void buttonTestScreenCapture_Click(object sender, EventArgs e)
{
    try
    {
        BitmapSource bms = CopyScreen();
        BitmapFrame bmf = BitmapFrame.Create(bms);

        PngBitmapEncoder encoder = new PngBitmapEncoder();
        encoder.Frames.Add(bmf);

        string filepath = @"e:\(test)\test.png";
        using (Stream stm = File.Create(filepath))
        {
            encoder.Save(stm);
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show($"Err={ex}");
    }
}

public class SafeHBitmapHandle : SafeHandleZeroOrMinusOneIsInvalid
{
    [System.Runtime.InteropServices.DllImport("gdi32.dll")]
    public static extern int DeleteObject(IntPtr hObject);

    [SecurityCritical]
    public SafeHBitmapHandle(IntPtr preexistingHandle, bool ownsHandle)
        : base(ownsHandle)
    {
        SetHandle(preexistingHandle);
    }

    protected override bool ReleaseHandle()
    {
        return DeleteObject(handle) > 0;
    }
}

And 2 finally a look at my 'usings':

using System;
using System.Linq;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Media.Imaging;
using System.Windows.Interop;
using System.Windows;
using System.IO;
using Microsoft.Win32.SafeHandles;
using System.Security;

The DLLs referenced 1 included: * PresentationCore * System.Core * System.Deployment * System.Drawing * WindowsBase

In my case it did not work directly with 2 this method. I had to add a clean garbage 1 collector in addition

    using (PaintMap p = new PaintMap())
    {
        System.Drawing.Image i = p.AddLineToMap("1");
        System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(i, 8419, 5953);
        IntPtr hBitmap = bmp.GetHbitmap();

        var bitmapSource = Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
        Image2.ImageSource = bitmapSource;

        DeleteObject(hBitmap);

        System.GC.Collect();
    }