WinForm--(控件的拖拽和跟隨鼠標移動)

實現控件的拖拽和跟隨鼠標移動

圖1（拖拽）:

 

圖2（鼠標點擊移動）：

代碼：

namespace TestSelect
{
    public partial class DragForm : Form
    {
        public DragForm()
        {
            InitializeComponent();
        }
        private void DragForm_Load(object sender, EventArgs e)
        {
            label1.MouseDown += new MouseEventHandler(mouseDown);
            label2.MouseDown += new MouseEventHandler(mouseDown);
            label3.MouseDown += new MouseEventHandler(mouseDown);

            this.panel2.DragEnter += new DragEventHandler(panelDragEnter);
            this.panel2.DragDrop += new DragEventHandler(panelDragDrop);
        }
        //鼠標按下事件，為拖放操作做准備
        void mouseDown(object sender, MouseEventArgs e)
        {
            DoDragDrop(sender, DragDropEffects.Move);
        }

        //當拖拽控件到容器上時發生
        private void panelDragEnter(object sender, DragEventArgs e)
        {

            object data = e.Data.GetData(typeof(Label));
            if (data != null)
            {
                e.Effect = DragDropEffects.Move;
            }
            else
            {
                e.Effect = DragDropEffects.None;
            }
        }

        //當完成拖拽操作時發生
        private void panelDragDrop(object sender, DragEventArgs e)
        {
            object data = e.Data.GetData(typeof(Label));
            Panel bpl = (Panel)sender;
            //在panel2中按鼠標位置移動標簽

            foreach (Label btn in this.panel1.Controls)
            {
                if (data == btn)
                {
                    Label lb = new Label();
                    lb.Text = btn.Text;
                    lb.BackColor = System.Drawing.Color.White;
                    bpl.Controls.Add(lb);//添加標簽
                    lb.Left = Control.MousePosition.X-this.Location.X ;
                    lb.BorderStyle = BorderStyle.FixedSingle;
                    lb.MouseDown += new MouseEventHandler(lable_MouseDown);
                    lb.MouseUp += new MouseEventHandler(lable_MouseUp);
                    lb.MouseMove += new MouseEventHandler(lable_MouseMove);
                 
                }
            }
        }
        //鼠標移動窗體移動
        private bool isMouseDown = false;
        private Point lableLocation;     //lable的location
        private Point mouseOffset;      //鼠標的按下位置
        private void lable_MouseDown(object sender, MouseEventArgs e)
        {

            if (e.Button == MouseButtons.Left)
            {
                isMouseDown = true;
                lableLocation = ((Label)sender).Location;
                mouseOffset = Control.MousePosition;
            }

        }

        private void lable_MouseUp(object sender, MouseEventArgs e)
        {
            isMouseDown = false;
        }

        private void lable_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;
                ((Label)sender).Location = new Point(lableLocation.X - _x, lableLocation.Y -_y);
            }

        }
    }
}

順便附上一張刻度圖（一格子一個像素）：