animation跑马灯动画实现两种方法

一时失言乱红尘 2023-10-17 02:25 18阅读 0赞

//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];

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