求大神指教，拖动无边框窗体

Question

我按照网上查找的代码写进去后，为什么还是不能实现拖动？

Answer 1

namespace WindowsFormsApplication5
{
    public partial class Form1 : Form
    {
        Point p1=new Point();
        bool drag = false;
        public Form1()
        {
            InitializeComponent();
        }        private void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                p1.X = e.X;
                p1.Y = e.Y;
                //drag = true;
            }
        }
        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            //if (drag == true)
            //{
                if (e.Button == MouseButtons.Left)
                {
                    this.Left = Control.MousePosition.X - p1.X - SystemInformation.FrameBorderSize.Width;
                    this.Top = Control.MousePosition.Y - p1.Y - SystemInformation.FrameBorderSize.Height - SystemInformation.CaptionHeight;
                }
            //}
        }
        private void Form1_MouseUp(object sender, MouseEventArgs e)
        {
            drag = false;
        }
    }
}
这样试着可以