//方法一
@interface ViewController ()@end@implementation ViewController
{UILabel * _label ;
}
- (void)viewDidLoad {[super viewDidLoad];_label  = [[UILabel alloc]initWithFrame:CGRectMake(0, 30, 100, 40)];_label.text = @"游来游去";_label.textAlignment= NSTextAlignmentCenter;_label.backgroundColor = [UIColor orangeColor];[self.view addSubview:_label];//实现从左到右[self leftToRight];
}-(void)rightToLeft
{//从右到左[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:4];_label.frame = CGRectMake(0, 30, 100, 40);[UIView setAnimationDelegate:self];[UIView setAnimationDidStopSelector:@selector(leftToRight)];[UIView commitAnimations];}-(void)leftToRight
{//实现从左到右[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:4];_label.frame = CGRectMake(320, 30, 100, 40);//设置谁去调用动画的结束方法(设置代理)[UIView setAnimationDelegate:self];//设置动画将要开始的方法[UIView setAnimationWillStartSelector:@selector(animationStart)];//设置动画的结束方法  谁什么情况下做什么事情[UIView setAnimationDidStopSelector:@selector(rightToLeft)];[UIView commitAnimations];NSLog(@"动画块的代码执行完了,但是动画还没有结束 ；代码的执行 和 动画的执行 是  并列 的");
}-(void)animationStart
{NSLog(@"动画要开始了");
}@end

//方法二
UILabel * label = [[UILabel alloc]initWithFrame:CGRectMake(0, 20, 100, 40)];label.backgroundColor = [UIColor purpleColor] ;label.text = @"跑马灯";[self.view addSubview:label];[UIView beginAnimations:nil context:nil];[UIView setAnimationDuration:2];//设置动画的重复次数  注意顺序；写在结束坐标点的上方；//LONG_MAX:无穷大[UIView setAnimationRepeatCount:LONG_MAX];//设置是否执行反向动画 ；[UIView setAnimationRepeatAutoreverses:YES];label.frame = CGRectMake(320, 20, 100, 40);[UIView commitAnimations];