ClipCursor

C# Signature:

[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern bool ClipCursor(ref RECT lpRect);

VB.Net Signature:

Private Declare Function ClipCursor Lib "user32"(ByRef lpRect As RECT) As Long

User-Defined Types:

public struct RECT
{
    #region Variables.
    /// <summary>
    /// Left position of the rectangle.
    /// </summary>
    public int Left;
    /// <summary>
    /// Top position of the rectangle.
    /// </summary>
    public int Top;
    /// <summary>
    /// Right position of the rectangle.
    /// </summary>
    public int Right;
    /// <summary>
    /// Bottom position of the rectangle.
    /// </summary>
    public int Bottom;
    #endregion

    #region Operators.
    /// <summary>
    /// Operator to convert a RECT to Drawing.Rectangle.
    /// </summary>
    /// <param name="rect">Rectangle to convert.</param>
    /// <returns>A Drawing.Rectangle</returns>
    public static implicit operator Rectangle(RECT rect)
    {
        return Rectangle.FromLTRB(rect.Left, rect.Top, rect.Right, rect.Bottom);
    }

    /// <summary>
    /// Operator to convert Drawing.Rectangle to a RECT.
    /// </summary>
    /// <param name="rect">Rectangle to convert.</param>
    /// <returns>RECT rectangle.</returns>
    public static implicit operator RECT(Rectangle rect)
    {
        return new RECT(rect.Left, rect.Top, rect.Right, rect.Bottom);
    }
    #endregion

    #region Constructor.
    /// <summary>
    /// Constructor.
    /// </summary>
    /// <param name="left">Horizontal position.</param>
    /// <param name="top">Vertical position.</param>
    /// <param name="right">Right most side.</param>
    /// <param name="bottom">Bottom most side.</param>
    public RECT(int left, int top, int right, int bottom)
    {
        Left = left;
        Top = top;
        Right = right;
        Bottom = bottom;
    }
    #endregion
}

Sample Code:

RECT rect =new RECT( 10, 10, 20, 20 );
ClipCursor(ref rect);