C#移动无边框窗体

我在VS C# 2008添加了 DotNetBar的RibbonBar 控件，想让界面更美观些，就把窗体改成了无边框的，可是这样就不能移动啦
想通过移动RibbonBar 控件来移动整个窗体
网上找到了很多版本的方法都不行，点在空白窗体处也移动不了
例如
private Point mouseOffset;
private bool isMouseDown = false;

private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
    int xOffset;
    int yOffset;

    if (e.Button == MouseButtons.Left)
    {
        xOffset = -e.X /*- SystemInformation.FrameBorderSize.Width*/;
        yOffset = -e.Y /*- SystemInformation.CaptionHeight - SystemInformation.FrameBorderSize.Height*/;
        mouseOffset = new Point(xOffset, yOffset);
        isMouseDown = true;
    }
}
private void Form1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
    if (isMouseDown)
    {
        Point mousePos = Control.MousePosition;
        mousePos.Offset(mouseOffset.X, mouseOffset.Y);
        Location = mousePos;
    }
}

private void Form1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
    if