核心动画 - CATransition

static int i = 1;

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    NSString *imageN = [NSString stringWithFormat:@"%d",i];
    
    _imageV.image = [UIImage imageNamed:imageN];
    
    i++;
}

 // 转场代码
    if (i == 4) {
        i = 1;
    }
    // 加载图片名称
    NSString *imageN = [NSString stringWithFormat:@"%d",i];
    
    _imageView.image = [UIImage imageNamed:imageN];
    
    i++;

static int i = 1;

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    if (i == 4) {
        i = 1;
    }
    
    NSString *imageN = [NSString stringWithFormat:@"%d",i];
    
    _imageV.image = [UIImage imageNamed:imageN];
    
    i++;
    
    // 转场动画
    CATransition *anim = [CATransition animation];
    anim.type = @"cube";
    [_imageV.layer addAnimation:anim forKey:nil];
}

 anim.type = @"cube";