iphone - 双击缩放 UIImageView

Question

我正在查看 Apple 的 ScrollViewSuite 示例代码。相比之下，我一定做错了什么。在他们的 RootViewController 中，他们这样做:

- (void)loadView {
    [super loadView];

    // set the tag for the image view
    [imageView setTag:ZOOM_VIEW_TAG];

    // add gesture recognizers to the image view
    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
    UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
    UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTwoFingerTap:)];

    [doubleTap setNumberOfTapsRequired:2];
    [twoFingerTap setNumberOfTouchesRequired:2];

    [imageView addGestureRecognizer:singleTap];
    [imageView addGestureRecognizer:doubleTap];
    [imageView addGestureRecognizer:twoFingerTap];

    [singleTap release];
    [doubleTap release];
    [twoFingerTap release];

    // calculate minimum scale to perfectly fit image width, and begin at that scale
    float minimumScale = [imageScrollView frame].size.width  / [imageView frame].size.width;
    [imageScrollView setMinimumZoomScale:minimumScale];
    [imageScrollView setZoomScale:minimumScale];
}

在 IB 中，他们将 imageView 作为 imageScrollView 的 subview 。我的 .xib 的设置方式相同。我将此代码放在 viewDidLoad 而不是 loadView 中。当我双击 imageView 时，我没有接到任何电话。我想知道为什么。这是我对他们所做的事情的版本:

- (void)viewDidLoad {
    [self updateOnScreenImages];  // this is where my imageView.image property gets set

    UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTap:)];
    doubleTap.numberOfTapsRequired = 2;

    UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTwoFingerTap:)];
    [doubleTap setNumberOfTouchesRequired:2];


    [self.imageView addGestureRecognizer:doubleTap];
    [self.imageView addGestureRecognizer:twoFingerTap];

    [doubleTap release];
    [twoFingerTap release];

}

与 Apple 所做的相比，我做的有什么问题吗？这个逻辑似乎和我很相似。但是当我双击时我没有收到回调。我也尝试将手势添加到 self.scrollView 中，但这也不起作用。想法？谢谢!

Answer 1

尝试添加:

   self.imageView.userInteractionEnabled = YES;

默认情况下，UIImageView将该属性设置为NO
(苹果可能已经在 XIB 文件中更改了它，并且您可能已经丢失了...)