How do I create a Cursor object from a Bitmap object?

Question

Assuming I have an existing System.Drawing.Bitmap object, how do I create a System.Windows.Forms.Cursor object with the same pixel data as my Bitmap object?

Answer 1

This answer is taken from this question. It allows you to both create a Cursor from a Bitmap object and set its hotspot.

public struct IconInfo
{
    public bool fIcon;
    public int xHotspot;
    public int yHotspot;
    public IntPtr hbmMask;
    public IntPtr hbmColor;
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetIconInfo(IntPtr hIcon, ref IconInfo pIconInfo);
[DllImport("user32.dll")]
public static extern IntPtr CreateIconIndirect(ref IconInfo icon);

/// <summary>
/// Create a cursor from a bitmap without resizing and with the specified
/// hot spot
/// </summary>
public static Cursor CreateCursorNoResize(Bitmap bmp, int xHotSpot, int yHotSpot)
{
    IntPtr ptr = bmp.GetHicon();
    IconInfo tmp = new IconInfo();
    GetIconInfo(ptr, ref tmp);
    tmp.xHotspot = xHotSpot;
    tmp.yHotspot = yHotSpot;
    tmp.fIcon = false;
    ptr = CreateIconIndirect(ref tmp);
    return new Cursor(ptr);
}


/// <summary>
/// Create a 32x32 cursor from a bitmap, with the hot spot in the middle
/// </summary>
public static Cursor CreateCursor(Bitmap bmp)
{
    int xHotSpot = 16;
    int yHotSpot = 16;

    IntPtr ptr = ((Bitmap)ResizeImage(bmp, 32, 32)).GetHicon();
    IconInfo tmp = new IconInfo();
    GetIconInfo(ptr, ref tmp);
    tmp.xHotspot = xHotSpot;
    tmp.yHotspot = yHotSpot;
    tmp.fIcon = false;
    ptr = CreateIconIndirect(ref tmp);
    return new Cursor(ptr);
}

Edit: As pointed out in the comments, when a Cursor is created from an IntPtr handle, disposing the cursor will not release the handle itself, which will create a memory leak unless you release it yourself manually using the DestroyIcon function:

[DllImport("user32.dll")]
private static extern bool DestroyIcon(IntPtr hIcon);

And then you can call the function like this:

DestroyIcon(myCursor.Handle);