转 实现类似QQ的窗体停靠

[DllImport("User32.dll")]
        public static extern bool PtInRect(ref Rectangle Rects, Point lpPoint);

        private void timerShowHide_Tick(object sender, EventArgs e)
        {
            if (this.WindowState == FormWindowState.Normal)
            {
                System.Drawing.Point cursorPoint = new Point(Cursor.Position.X, Cursor.Position.Y);//获取鼠标在屏幕的坐标点
                Rectangle Rects = new Rectangle(this.Left, this.Top, this.Left + this.Width, this.Top + this.Height);//存储当前窗体在屏幕的所在区域
                bool prInRect = PtInRect(ref Rects, cursorPoint);
                if (prInRect)
                {//当鼠标在当前窗体内
                    if (this.Top < 0)//窗体的Top属性小于0
                        this.Top = 0;
                    else if (this.Left < 0)//窗体的Left属性小于0
                        this.Left = 0;
                    else if (this.Right > Screen.PrimaryScreen.WorkingArea.Width)//窗体的Right属性大于屏幕宽度
                        this.Left = Screen.PrimaryScreen.WorkingArea.Width - this.Width;
                }
                else
                {
                    if (this.Top < 5)               //当窗体的上边框与屏幕的顶端的距离小于5时
                        this.Top = 5 - this.Height; //将窗体隐藏到屏幕的顶端
                    else if (this.Left < 5)         //当窗体的左边框与屏幕的左端的距离小于5时
                        this.Left = 5 - this.Width; //将窗体隐藏到屏幕的左端
                    else if (this.Right > Screen.PrimaryScreen.WorkingArea.Width - 5)//当窗体的右边框与屏幕的右端的距离小于5时
                        this.Left = Screen.PrimaryScreen.WorkingArea.Width - 5;//将窗体隐藏到屏幕的右端
                }
            }
        }