WinForm 拖动控件

private Point mouseOffset;
private void label1_MouseDown(object sender, MouseEventArgs e)
{
    mouseOffset = new Point(-e.X, -e.Y);
}

private void label1_MouseMove(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        Point mousePos = Control.MousePosition;
        mousePos.Offset(mouseOffset.X, mouseOffset.Y);
        ((Control)sender).Location = ((Control)sender).Parent.PointToClient(mousePos);
    }
}