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;

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,0);
   }

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 = 0;
    int _y = 0;
    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);
    }
}