dhr(dh, 0, 720, 1, 0.5, 1, 0.5)
 dh(dh, "duration", 3000)
 us(控件id, "dh", dh)
 dhon(dh)
 {
 us(控件id, "dh", dh)
 }
//此方法同样适用于其它控件，实现控件的无限旋转