1  Point mouseOff;//鼠标移动位置变量
 2         bool leftFlag;//标记是否为左键
 3         private void Form1_MouseDown(object sender, MouseEventArgs e)
 4         {
 5             if (e.Button == MouseButtons.Left)
 6             {
 7                 mouseOff = new Point(-e.X, -e.Y); //得到变量的值
 8                 leftFlag = true;                  //点击左键按下时标注为true;
 9             }
10         }
11 
12         private void Form1_MouseMove(object sender, MouseEventArgs e)
13         {
14             if (leftFlag)
15             {
16                 Point mouseSet = Control.MousePosition;
17                 mouseSet.Offset(mouseOff.X, mouseOff.Y);  //设置移动后的位置
18                 Location = mouseSet;
19             }
20         }
21 
22         private void Form1_MouseUp(object sender, MouseEventArgs e)
23         {
24             if (leftFlag)
25             {
26                 leftFlag = false;//释放鼠标后标注为false;
27             }
28         }