最近做一个及时通讯系统的登录界面，现在将界面用到的无边框、可拖拽、四周圆角的方法分享如下：

1、无边框的窗体： 把FormBorderStyle的属性设置为none

2、可拖拽：private Point mPoint = new Point();

private void FormLogin_MouseDown(object sender, MouseEventArgs e)
        {
            mPoint.X = e.X;
            mPoint.Y = e.Y;
        }

private void FormLogin_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                Point myPosittion = MousePosition;
                myPosittion.Offset(-mPoint.X, -mPoint.Y);
                Location = myPosittion;
            }
        }

3、四周圆角：

　　private void FormLogin_Resize(object sender, EventArgs e)
        {
            SetWindowRegion();
        }

public void SetWindowRegion()
        {
            System.Drawing.Drawing2D.GraphicsPath FormPath;
            FormPath = new System.Drawing.Drawing2D.GraphicsPath();
            Rectangle rect = new Rectangle(0, 0, this.Width, this.Height);
            FormPath = GetRoundedRectPath(rect, 10);
            this.Region = new Region(FormPath);

}
        private GraphicsPath GetRoundedRectPath(Rectangle rect, int radius)
        {
            int diameter = radius;
            Rectangle arcRect = new Rectangle(rect.Location, new Size(diameter, diameter));
            GraphicsPath path = new GraphicsPath();

// 左上角
            path.AddArc(arcRect, 180, 90);

// 右上角
            arcRect.X = rect.Right - diameter;
            path.AddArc(arcRect, 270, 90);

// 右下角
            arcRect.Y = rect.Bottom - diameter;
            path.AddArc(arcRect, 0, 90);

// 左下角
            arcRect.X = rect.Left;
            path.AddArc(arcRect, 90, 90);
            path.CloseFigure();//闭合曲线
            return path;
        }