c#实现随鼠标移动窗体

窗体没有标题的情况下

private Point mousePoint;
private void Form1_MouseMove(object sender, MouseEventArgs e)
        {            
            if (e.Button == MouseButtons.Left)
            {
               this.Top = Control.MousePosition.Y - mousePoint.Y;
                this.Left = Control.MousePosition.X - mousePoint.X;
            }
        }

        private void Form1_MouseDown(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                this.mousePoint.X = e.X;
                this.mousePoint.Y = e.Y;
            }
        }





如果窗体有标题 
Top -= SystemInformation.CaptionHeight;

如果有边框 
Top -= SystemInformation.FormBorderSize.Height
Left -= SystemInformation.FormBorderSize.Width