iphone - 检测 UIImageView 上的触摸事件

Question

我在 UIView 上放置了 4 个 UIImageView 并给它们命名

UIImageView myImg1 = [[UIImageView alloc] init];     
UIImageView myImg2 = [[UIImageView alloc] init];     
UIImageView myImg3 = [[UIImageView alloc] init]; 
UIImageView myImg4 = [[UIImageView alloc] init];

我如何告诉编译器我刚刚接触了 UIImageView 1 或 UIImaveView 2。如果我只能使用 UIImageView 来完成此任务，而根本不能使用按钮。请指导我解决这个问题。谢谢

Answer 1

一个时尚的解决方案是使用 UIGestureRecognizer 对象:

在您的 loadView 方法中(或在您编写 UIImageView 绘图代码的任何地方...):

   UITapGestureRecognizer *tapRecognizer;
    UIImageView *anImageView = [[UIImageView alloc] initWithFrame:CGRectMake(20, 20, 100, 100)];
    [anImageView setTag:0]; //Pay attention here!, Tag is used to distinguish between your UIImageView on the selector
    [anImageView setBackgroundColor:[UIColor redColor]];
    [anImageView setUserInteractionEnabled:TRUE];
    tapRecognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageViewDidTapped:)] autorelease];
    tapRecognizer.numberOfTapsRequired = 1;
    [anImageView addGestureRecognizer:tapRecognizer];
    [contentView addSubview:anImageView];
    [anImageView release];

    UIImageView *anotherImageView = [[UIImageView alloc] initWithFrame:CGRectMake(80, 180, 100, 100)];
    [anotherImageView setTag:1]; //Pay attention here!, Tag is used to distinguish between your UIImageView on the selector
    [anotherImageView setBackgroundColor:[UIColor greenColor]];
    [anotherImageView setUserInteractionEnabled:TRUE];
    tapRecognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageViewDidTapped:)] autorelease];
    tapRecognizer.numberOfTapsRequired = 1;
    [anotherImageView addGestureRecognizer:tapRecognizer];
    [contentView addSubview:anotherImageView];
    [anotherImageView release];

这是一个简单的 imageViewDidTapped: 示例方法，您可以使用它来区分上面的两个示例 UIImageView 对象:

- (void)imageViewDidTapped:(UIGestureRecognizer *)aGesture {
    UITapGestureRecognizer *tapGesture = (UITapGestureRecognizer *)aGesture;

    UIImageView *tappedImageView = (UIImageView *)[tapGesture view];

    switch (tappedImageView.tag) {
        case 0:
            NSLog(@"UIImageView 1 was tapped");
            break;
        case 1:
            NSLog(@"UIImageView 2 was tapped");
            break;
        default:
            break;
    }
}