我正在查看苹果公司ScrollViewSuite的示例代码。相比之下,我的某些地方可能做错了。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,他们将他们的imageView作为imageScrollView的子视图。 我的.xib也是这样设置的。 我把这段代码放在了viewDidLoad而不是loadView中。但是当我双击imageView时,我没有收到任何调用。 我想知道原因。以下是我的版本:
- (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];
}
相比于苹果的做法,我是否有做错什么?在我看来逻辑是相似的。但是当我双击时,我的回调函数没有被调用。我尝试将手势添加到self.scrollView中,但也不起作用。有什么想法吗?谢谢!