拖动窗体的两种方法

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private Point myPoint;//提供有序的 x 坐标和 y 坐标整数对，该坐标对在二维平面中定义一个点。

        /// <summary>
        /// 鼠标按下去后抬起时触发
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form4_MouseUp(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)//按下鼠标左键
            {
                Point myPosition = Control.MousePosition;//鼠标光标位置的新实例
                myPosition.Offset(myPoint.X, myPoint.Y);//光标平移指定的量
                this.DesktopLocation = myPosition;//设置桌面上的窗体的位置
            }
        }

        /// <summary>
        /// 鼠标移动到控件上时触发
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form4_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)//按下鼠标左键
            {
                Point myPosition = Control.MousePosition;//鼠标光标位置的新实例
                myPosition.Offset(myPoint.X, myPoint.Y);//光标平移指定的量
                this.DesktopLocation = myPosition;//设置桌面上的窗体的位置
            }
        }

        /// <summary>
        /// 鼠标按下去时触发
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form4_MouseDown(object sender, MouseEventArgs e)
        {
            myPoint = new Point(-e.X, -e.Y);//记录光标移动的量
        }

        //鼠标移动到控件上，触发Form4_MouseMove，如果鼠标点的是左键就会同时触发Form4_MouseDown。
        //在Form4_MouseDown中会记录光标移动的量，然后Form4_MouseMove中会根据这个量来设定窗体的位置。
        //鼠标抬起时触发Form4_MouseUp，Form4_MouseUp中也会根据Form4_MouseDown中记录的光标移动的量设置
        //窗体的位置。
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication3
{
    public partial class Form5 : Form
    {
        public Form5()
        {
            InitializeComponent();
        }
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [System.Runtime.InteropServices.DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;
        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
            try
            {
                ReleaseCapture();
                SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
            }
            catch

            { }
        }
    }
}