UIView動畫With Block

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.smallRect = CGRectMake(0, 0, 20, 30);
    self.bigRect = CGRectMake(0, 0, 200, 300);
    //創建一個按鈕
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    btn.backgroundColor = [UIColor lightGrayColor];
    [btn addTarget:self action:@selector(onPressButton:) forControlEvents:UIControlEventTouchUpInside];
    btn.frame = CGRectMake(150, 300, 120, 30);
    [self.view addSubview:btn];
    
    //創建imgView
    self.imgview = [[UIImageView alloc] initWithFrame:_smallRect];
    _imgview.backgroundColor = [UIColor redColor];
    [self.view addSubview:_imgview];

}


//button觸發事件
-(void)onPressButton:(id)sender
{
    //*************第一種   動畫blcok  **********
    [UIView animateWithDuration:2 animations:^{
        _imgview.frame = self.bigRect;
    }];
   
     //*************第二種   動畫blcok  **********
    
    //帶一個回調
    [UIView animateWithDuration:2 animations:^{
        self.imgview.frame = self.bigRect;
    } completion:^(BOOL finished) {
        self.imgview.backgroundColor = [UIColor blackColor];
    }];
    
    
    //*************第三種   動畫blcok  **********
    //帶一個延遲
    [UIView animateWithDuration:2 delay:5 options:UIViewAnimationOptionAutoreverse animations:^{
        self.imgview.frame = self.bigRect;
    } completion:^(BOOL finished) {
        if (finished) {
            self.imgview.backgroundColor = [UIColor blackColor];
        }
    }];
}