Custom cursor in WPF?

Question

I want to use an image or icon as a custom cursor in WPF app. What's the best way to do it?

Answer 1

In case anyone is looking for a UIElement itself as a cursor, I combined the solutions of Ray and Arcturus:

    public Cursor ConvertToCursor(UIElement control, Point hotSpot)
    {
        // convert FrameworkElement to PNG stream
        var pngStream = new MemoryStream();
        control.Measure(new Size(double.PositiveInfinity, double.PositiveInfinity));
        Rect rect = new Rect(0, 0, control.DesiredSize.Width, control.DesiredSize.Height);
        RenderTargetBitmap rtb = new RenderTargetBitmap((int)control.DesiredSize.Width, (int)control.DesiredSize.Height, 96, 96, PixelFormats.Pbgra32);

        control.Arrange(rect);
        rtb.Render(control);

        PngBitmapEncoder png = new PngBitmapEncoder();
        png.Frames.Add(BitmapFrame.Create(rtb));
        png.Save(pngStream);

        // write cursor header info
        var cursorStream = new MemoryStream();
        cursorStream.Write(new byte[2] { 0x00, 0x00 }, 0, 2);                               // ICONDIR: Reserved. Must always be 0.
        cursorStream.Write(new byte[2] { 0x02, 0x00 }, 0, 2);                               // ICONDIR: Specifies image type: 1 for icon (.ICO) image, 2 for cursor (.CUR) image. Other values are invalid
        cursorStream.Write(new byte[2] { 0x01, 0x00 }, 0, 2);                               // ICONDIR: Specifies number of images in the file.
        cursorStream.Write(new byte[1] { (byte)control.DesiredSize.Width }, 0, 1);          // ICONDIRENTRY: Specifies image width in pixels. Can be any number between 0 and 255. Value 0 means image width is 256 pixels.
        cursorStream.Write(new byte[1] { (byte)control.DesiredSize.Height }, 0, 1);         // ICONDIRENTRY: Specifies image height in pixels. Can be any number between 0 and 255. Value 0 means image height is 256 pixels.
        cursorStream.Write(new byte[1] { 0x00 }, 0, 1);                                     // ICONDIRENTRY: Specifies number of colors in the color palette. Should be 0 if the image does not use a color palette.
        cursorStream.Write(new byte[1] { 0x00 }, 0, 1);                                     // ICONDIRENTRY: Reserved. Should be 0.
        cursorStream.Write(new byte[2] { (byte)hotSpot.X, 0x00 }, 0, 2);                    // ICONDIRENTRY: Specifies the horizontal coordinates of the hotspot in number of pixels from the left.
        cursorStream.Write(new byte[2] { (byte)hotSpot.Y, 0x00 }, 0, 2);                    // ICONDIRENTRY: Specifies the vertical coordinates of the hotspot in number of pixels from the top.
        cursorStream.Write(new byte[4] {                                                    // ICONDIRENTRY: Specifies the size of the image's data in bytes
                                          (byte)((pngStream.Length & 0x000000FF)),
                                          (byte)((pngStream.Length & 0x0000FF00) >> 0x08),
                                          (byte)((pngStream.Length & 0x00FF0000) >> 0x10),
                                          (byte)((pngStream.Length & 0xFF000000) >> 0x18)
                                       }, 0, 4);
        cursorStream.Write(new byte[4] {                                                    // ICONDIRENTRY: Specifies the offset of BMP or PNG data from the beginning of the ICO/CUR file
                                          (byte)0x16,
                                          (byte)0x00,
                                          (byte)0x00,
                                          (byte)0x00,
                                       }, 0, 4);

        // copy PNG stream to cursor stream
        pngStream.Seek(0, SeekOrigin.Begin);
        pngStream.CopyTo(cursorStream);

        // return cursor stream
        cursorStream.Seek(0, SeekOrigin.Begin);
        return new Cursor(cursorStream);
    }

Answer 2

Here's a feature-rich, free utility that allows you to create a cur file from any image: http://www.rw-designer.com/cursor-maker

It's called RealWorld Cursor Editor.

And here's a link on how to embed a cursor in a project:

http://wpf.2000things.com/tag/cursor/

Answer 3

you can do this by Code like

this.Cursor = new Cursor(@"<your address of icon>");

Answer 4

One more solution somewhat similar to Ray's but instead of slow and cumbersome pixel copying, this uses some Windows internals:

private struct IconInfo {
  public bool fIcon;
  public int xHotspot;
  public int yHotspot;
  public IntPtr hbmMask;
  public IntPtr hbmColor;
}

[DllImport("user32.dll")]
private static extern IntPtr CreateIconIndirect(ref IconInfo icon);

[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool GetIconInfo(IntPtr hIcon, ref IconInfo pIconInfo);

public Cursor ConvertToCursor(FrameworkElement cursor, Point HotSpot) {
  cursor.Arrange(new Rect(new Size(cursor.Width, cursor.Height)));
  var bitmap = new RenderTargetBitmap((int)cursor.Width, (int)cursor.Height, 96, 96, PixelFormats.Pbgra32);
  bitmap.Render(cursor);

  var info = new IconInfo();
  GetIconInfo(bitmap.ToBitmap().GetHicon(), ref info);
  info.fIcon = false;
  info.xHotspot = (byte)(HotSpot.X * cursor.Width);
  info.yHotspot = (byte)(HotSpot.Y * cursor.Height);

  return CursorInteropHelper.Create(new SafeFileHandle(CreateIconIndirect(ref info), true));
}

There is an extension method in the middle that I prefer to have in an extension class for such cases:

using DW = System.Drawing;

public static DW.Bitmap ToBitmap(this BitmapSource bitmapSource) {
  var bitmap = new DW.Bitmap(bitmapSource.PixelWidth, bitmapSource.PixelHeight, DW.Imaging.PixelFormat.Format32bppPArgb);
  var data = bitmap.LockBits(new DW.Rectangle(DW.Point.Empty, bitmap.Size), DW.Imaging.ImageLockMode.WriteOnly, DW.Imaging.PixelFormat.Format32bppPArgb);
  bitmapSource.CopyPixels(Int32Rect.Empty, data.Scan0, data.Height * data.Stride, data.Stride);
  bitmap.UnlockBits(data);
  return bitmap;
}

With all this, it's rather simple and straightforward.

And, if you happen not to need to specify your own hotspot, you can even cut this shorter (you don't need the struct or the P/Invokes, either):

public Cursor ConvertToCursor(FrameworkElement cursor, Point HotSpot) {
  cursor.Arrange(new Rect(new Size(cursor.Width, cursor.Height)));
  var bitmap = new RenderTargetBitmap((int)cursor.Width, (int)cursor.Height, 96, 96, PixelFormats.Pbgra32);
  bitmap.Render(cursor);
  var icon = System.Drawing.Icon.FromHandle(bitmap.ToBitmap().GetHicon());
  return CursorInteropHelper.Create(new SafeFileHandle(icon.Handle, true));
}

Answer 5

Make sure, that any GDI resource (for example bmp.GetHIcon) gets disposed. Otherwise you end up with a memory leak. The following code (extension method for icon) works perfectly for WPF. It creates the arrow cursor with a small icon on it's lower right.

Remark: This code uses an icon to create the cursor. It does not use a current UI control.

Matthias

    public static Cursor CreateCursor(this Icon icon, bool includeCrossHair, System.Drawing.Color crossHairColor)
    {
        if (icon == null)
            return Cursors.Arrow;

        // create an empty image
        int width = icon.Width;
        int height = icon.Height;

        using (var cursor = new Bitmap(width * 2, height * 2))
        {
            // create a graphics context, so that we can draw our own cursor
            using (var gr = System.Drawing.Graphics.FromImage(cursor))
            {
                // a cursor is usually 32x32 pixel so we need our icon in the lower right part of it
                gr.DrawIcon(icon, new Rectangle(width, height, width, height));

                if (includeCrossHair)
                {
                    using (var pen = new System.Drawing.Pen(crossHairColor))
                    {
                        // draw the cross-hair
                        gr.DrawLine(pen, width - 3, height, width + 3, height);
                        gr.DrawLine(pen, width, height - 3, width, height + 3);
                    }
                }
            }

            try
            {
                using (var stream = new MemoryStream())
                {
                    // Save to .ico format
                    var ptr = cursor.GetHicon();
                    var tempIcon = Icon.FromHandle(ptr);
                    tempIcon.Save(stream);

                    int x = cursor.Width/2;
                    int y = cursor.Height/2;

                    #region Convert saved stream into .cur format

                    // set as .cur file format
                    stream.Seek(2, SeekOrigin.Begin);
                    stream.WriteByte(2);

                    // write the hotspot information
                    stream.Seek(10, SeekOrigin.Begin);
                    stream.WriteByte((byte)(width));
                    stream.Seek(12, SeekOrigin.Begin);
                    stream.WriteByte((byte)(height));

                    // reset to initial position
                    stream.Seek(0, SeekOrigin.Begin);

                    #endregion


                    DestroyIcon(tempIcon.Handle);  // destroy GDI resource

                    return new Cursor(stream);
                }
            }
            catch (Exception)
            {
                return Cursors.Arrow;
            }
        }
    }

    /// <summary>
    /// Destroys the icon.
    /// </summary>
    /// <param name="handle">The handle.</param>
    /// <returns></returns>
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public extern static Boolean DestroyIcon(IntPtr handle);

Answer 6

If you are using visual studio, you can

1. New a cursor file
2. Copy/Paste the image
3. Save it to .cur file.