Cocoa touch 滚动时跟踪UIPageController中的frame.origin.x
我在这里使用标准UIPageViewController,我需要跟踪x坐标,以便相应地更改图像的alpha。我尝试在UIPageViewController中找到UIScrollView,如下所示:Cocoa touch 滚动时跟踪UIPageController中的frame.origin.x,cocoa-touch,uiscrollview,uikit,uipageviewcontroller,Cocoa Touch,Uiscrollview,Uikit,Uipageviewcontroller,我在这里使用标准UIPageViewController,我需要跟踪x坐标,以便相应地更改图像的alpha。我尝试在UIPageViewController中找到UIScrollView,如下所示: for (UIView *view in self.pageViewController.view.subviews) { if ([view isKindOfClass:[UIScrollView class]]) { [(UIScrollView *)view setDe
for (UIView *view in self.pageViewController.view.subviews) {
if ([view isKindOfClass:[UIScrollView class]]) {
[(UIScrollView *)view setDelegate:self];
}
}
但当我这么做的时候:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
MTWPageContentViewController *pageContentVC = [self viewControllerAtIndex:_mainPageControl.currentPage];
NSLog(@"%f", pageContentVC.view.frame.origin.x);
}
NSLog给了我0.000,这显然意味着我做错了什么
pageContentVC存在,它是在我滚动时可见的视图控制器。
那么,告诉我如何在滚动时跟踪UIPageViewController子视图的x坐标 您可以从UIPageViewController获取手势识别器,并将自己添加为目标/动作,以获取有关pan的信息
for (UIGestureRecognizer *gestureRecognizer in self.pageViewController.gestureRecognizers) {
if ([gestureRecognizer isKindOfClass:UIPanGestureRecognizer.class]) {
[gestureRecognizer addTarget:self action:@selector(panned:)];
}
}
谢谢那么,如何使用手势识别器获取x坐标呢?