C#中通过拖动控件来拖动窗体

之前介绍的C#实现用户区左键拖动窗体效果(非标题栏)是通过鼠标点着窗体空白区域然后来拖动窗体，这里介绍的是在C#中鼠标点着某个控件不放来拖动整个窗体。

首先引入命名空间

using System.Runtime.InteropServices;

#region   点击控件移动窗体
[DllImportAttribute("user32.dll")]
private extern static bool ReleaseCapture();
[DllImportAttribute("user32.dll")]
private extern static int SendMessage(IntPtr handle, int m, int p, int h);
#endregion
private void label1_MouseDown(object sender, MouseEventArgs e)
{
     //点击控件移动窗体
     if (e.Button == MouseButtons.Left)
     {
          Cursor= Cursors.SizeAll;//改变鼠标样式
          ReleaseCapture();
          SendMessage(this.Handle, 0xA1, 0x2, 0);
          Cursor = Cursors.Default;
     }
}