using System.Windows.Forms; namespace WinFormsApp_DragControls {     public class DragControl     {         //待拖动的控件         private Control m_Control;         //鼠标按下时的x，y坐标         private int m_X;         private int m_Y;         public DragControl(Control control)         {             m_Control = control;             m_Control.MouseDown += new MouseEventHandler(control_MouseDown);             m_Control.MouseMove += new MouseEventHandler(contro_MouseMove);         }         private void control_MouseDown(object sender, MouseEventArgs e)         {             m_X = e.X;             m_Y = e.Y;         }         private void contro_MouseMove(object sender, MouseEventArgs e)         {             if (e.Button == MouseButtons.Left)             {                 int x = e.X - m_X;                 int y = e.Y - m_Y;                 this.m_Control.Left += x;                 this.m_Control.Top += y;             }         }     } }