实现控件的拖动

窗体属性设置：

代码如下：

        private void button1_MouseDown(object sender, MouseEventArgs e)
        {
            DoDragDrop(button1,DragDropEffects.Move);
        }

        private void Form7_DragDrop(object sender, DragEventArgs e)
        {
            object data = e.Data.GetData(typeof(Button));
            if (button1 == data)
            {
                button1.Top = this.PointToClient(new Point(e.X,e.Y)).Y;
                button1.Left= this.PointToClient(new Point(e.X, e.Y)).X;
            }
        }

        private void Form7_DragEnter(object sender, DragEventArgs e)
        {
            object data = e.Data.GetData(typeof(Button));
            if(data!=null)
            {
                e.Effect = DragDropEffects.Move;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }