C# WinForm 窗体移动事件实现

C# WinForm的FormBorderStyle设置为none，运行时窗体无法随鼠标移动，可以通过下面三个事件实现：

#region  拖动窗体的实现

        private Point mouseOff;//鼠标移动位置变量
        private bool leftFlag;//标签是否为左键
        private void FrmMain_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseOff = new Point(-e.X, -e.Y); //得到变量的值
                leftFlag = true;                  //点击左键按下时标注为true;
            }
        }
        private void FrmMain_MouseMove(object sender, MouseEventArgs e)
        {
            if (leftFlag)
            {
                Point mouseSet = Control.MousePosition;
                mouseSet.Offset(mouseOff.X, mouseOff.Y);  //设置移动后的位置
                Location = mouseSet;
            }
        }
        private void FrmMain_MouseUp(object sender, MouseEventArgs e)
        {
            if (leftFlag)
            {
                leftFlag = false;//释放鼠标后标注为false;
            }
        }

        #endregion