自由拖动的控件

/Files/tssing/MoveControl.rar

 

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
namespace WindowsFormsApplication8
{
    public class MoveButton:Button
    {
        bool IsMoving = false;
        Point pCtrlLastCoordinate = new Point(0, 0);
        Point pCursorOffset = new Point(0, 0);
        Point pCursorLastCoordinate = new Point(0, 0);

        public MoveButton()
        {
            InitializeComponent();
        }

        private void InitializeComponent()
        {
            this.SuspendLayout();
            // 
            // MoveButton
            // 
            this.MouseMove += new System.Windows.Forms.MouseEventHandler(this.MoveButton_MouseMove);
            this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.MoveButton_MouseDown);
            this.MouseUp += new System.Windows.Forms.MouseEventHandler(this.MoveButton_MouseUp);
            this.ResumeLayout(false);

        }

        private void MoveButton_MouseDown(object sender, MouseEventArgs e)
        {          
            if (e.Button == MouseButtons.Left)
            {
                IsMoving = true;
                pCtrlLastCoordinate.X = Left;
                pCtrlLastCoordinate.Y = Top;
                pCursorLastCoordinate.X = Cursor.Position.X;
                pCursorLastCoordinate.Y = Cursor.Position.Y;
            }
        }

        private void MoveButton_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                if (this.IsMoving)
                {
                    Point pCursor = new Point(Cursor.Position.X, Cursor.Position.Y);

                    pCursorOffset.X = pCursor.X - pCursorLastCoordinate.X;
                    pCursorOffset.Y = pCursor.Y - pCursorLastCoordinate.Y;
                    Left = pCtrlLastCoordinate.X + pCursorOffset.X;
                    Top = pCtrlLastCoordinate.Y + pCursorOffset.Y;
                }
            }
        }

        private void MoveButton_MouseUp(object sender, MouseEventArgs e)
        {
            if (this.IsMoving)
            {
                if (pCursorOffset.X == 0 && pCursorOffset.Y == 0)
                {
                    return;
                }
                if ((pCtrlLastCoordinate.X + pCursorOffset.X + Width) > 0)
                {
                    Left = pCtrlLastCoordinate.X + pCursorOffset.X;
                }
                else
                {
                    Left = 0;
                }
                if ((pCtrlLastCoordinate.Y + pCursorOffset.Y + Height) > 0)
                {
                    Top = pCtrlLastCoordinate.Y + pCursorOffset.Y;
                }
                else
                {
                    Top = 0;
                }
                pCursorOffset.X = 0;
                pCursorOffset.Y = 0;
            }
        }
    }
}