如何用C#实现控件的自由拖动

private Point mouse_offset;
private void label1_MouseDown(object sender, MouseEventArgs e)
{
mouse_offset = new Point(-e.X, -e.Y);//
}
private void label1_MouseMove(object sender, MouseEventArgs e)
{

((Control)sender).Cursor = Cursors.Arrow;//设置拖动时鼠标箭头
if (e.Button == MouseButtons.Left)
{
Point mousePos = Control.MousePosition;
mousePos.Offset(mouse_offset.X, mouse_offset.Y);//设置偏移
((Control)sender).Location = ((Control)sender).Parent.PointToClient(mousePos);
}
}