直接上代码：

[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                }            }        }