Animation

    //图片开始动画
    [UIView beginAnimations:nil context:nil];
    //动画的时间是...    typedef double NSTimeInterval;是double
    [UIView setAnimationDuration:(size.width+100)/30];
    //动画的曲线是...     对比火车进出站
    [UIView setAnimationCurve:UIViewAnimationCurveLinear];
    
    //动画的代理是自己
    [UIView setAnimationDelegate:self];
    //动画结束执行的方法
    [UIView setAnimationDidStopSelector:@selector(aniFinish)];
    
    //设置内容
    _label.frame=CGRectMake(-size.width, 0, size.width, size.height);
    
    //提交动画
    [UIView commitAnimations];