C#之设置无边框后如何移动窗体（转）

转载：http://www.cnblogs.com/techmango/archive/2012/03/31/2427523.html

第一种，利用windows的消息机制来实现：

首先﹐.定义鼠標左鍵按下時的Message标识﹔其次﹐在Form1_MouseDown方法﹐讓操作系統誤以為是按下标题栏。

1.定义鼠標左鍵按下時的Message标识

    private const int WM_NCLBUTTONDOWN = 0XA1;   //.定义鼠標左鍵按下
    private const int HTCAPTION     = ;

2.讓操作系統誤以為是按下标题栏

 private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    {
     //為當前的應用程序釋放鼠標鋪獲
     ReleaseCapture();
     //發送消息﹐讓系統誤以為在标题栏上按下鼠標
     SendMessage((int)this.Handle,WM_NCLBUTTONDOWN,HTCAPTION,);
    }

3.申明程序中所Windows的API函數

    [DllImport("user32.dll",EntryPoint="SendMessageA")]
    private static extern int SendMessage(int hwnd,int wMsg,int wParam,int lParam);

    [DllImport("user32.dll")]
    private static extern int ReleaseCapture();

第二种，通过自定鼠标左键按下时产生的事件:

* 首先将窗体的边框样式修改为None，让窗体没有标题栏
 * 实现这个效果使用了三个事件：鼠标按下、鼠标弹起、鼠标移动
 * 鼠标按下时更改变量isMouseDown标记窗体可以随鼠标的移动而移动
 * 鼠标移动时根据鼠标的移动量更改窗体的location属性，实现窗体移动
 * 鼠标弹起时更改变量isMouseDown标记窗体不可以随鼠标的移动而移动
 */

 private bool isMouseDown = false;
 private Point FormLocation;     //form的location
 private Point mouseOffset;      //鼠标的按下位置

 private void Form1_MouseDown(object sender, MouseEventArgs e)
 {
     if (e.Button == MouseButtons.Left)
     {
         isMouseDown = true;
         FormLocation = this.Location;
         mouseOffset = Control.MousePosition;
     }
 }

 private void Form1_MouseUp(object sender, MouseEventArgs e)
 {
     isMouseDown = false;
 }

 private void Form1_MouseMove(object sender, MouseEventArgs e)
 {
     int _x = ;
     int _y = ;
     if (isMouseDown)
     {
         Point pt = Control.MousePosition;
         _x = mouseOffset.X - pt.X;
         _y = mouseOffset.Y - pt.Y;

         this.Location = new Point(FormLocation.X - _x, FormLocation.Y - _y);
     }
 }