ios - 当 scrollView 设置 pagingEnabled 为 YES 时，点击 ScrollView 调用 `scrollViewWillBeginDecelerating`

Question

当我点击 ScrollView 时，它会调用方法 scrollViewWillBeginDecelerating 和 scrollViewDidEndDecelerating 甚至在 scrollView's 设置为 pagingEnabled 之后是

我有 scrollView 和 subViews 并尝试根据 subViews 设置 contentOffset。但它不起作用。

这是我的代码:

self.myScrollView.frame = CGRectMake(0, 0, pageWidth, pageHeight);
self.myScrollView.contentSize = CGSizeMake(pageWidth * self.contentViewControllers.count, pageHeight);

for (NSInteger i = 0; i < self.contentViewControllers.count; i++) {
    UILabel *label = [UILabel new];
    label.textColor = [UIColor whiteColor];
    label.textAlignment = NSTextAlignmentCenter;
    label.text = [NSString stringWithFormat:@"Page %ld",i];
    label.backgroundColor = [UIColor randomColor];
    label.frame = CGRectMake(i * pageWidth, 0, pageWidth, pageHeight);
    [self.myScrollView addSubview:label];
}

self.myScrollView.contentInset = UIEdgeInsetsMake(120, 0, 0, 0);
self.myScrollView.contentOffset = CGPointMake(0, - 120);
self.myScrollView.scrollIndicatorInsets = UIEdgeInsetsMake(120, 0, 0, 0);

- (UIScrollView *)myScrollView{
if (!_myScrollView) {
    _myScrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
    _myScrollView.backgroundColor = [UIColor blackColor];
    _myScrollView.pagingEnabled = YES;
    _myScrollView.directionalLockEnabled = YES;
    _myScrollView.delegate = self;
    //_myScrollView.delaysContentTouches = NO;
    //_myScrollView.scrollsToTop = NO;
}

return _myScrollView;
}

当我点击 scrollView 中的任何 subView 时，它会调用委托(delegate)方法:

scrollViewWillBeginDecelerating >> scrollViewDidScroll >> scrollViewDidEndDecelerating

contentOffset 更改为 {0,0}

Answer 1

请像这样更新您的代码:

请在for循环后设置contentSize。

self.myScrollView.frame = CGRectMake(0, 0, pageWidth, pageHeight);

for (NSInteger i = 0; i < self.contentViewControllers.count; i++) {
    UILabel *label = [UILabel new];
    label.textColor = [UIColor whiteColor];
    label.textAlignment = NSTextAlignmentCenter;
    label.text = [NSString stringWithFormat:@"Page %ld",i];
    label.backgroundColor = [UIColor randomColor];
    label.frame = CGRectMake(i * pageWidth, 0, pageWidth, pageHeight);
    [self.myScrollView addSubview:label];
}

self.myScrollView.contentInset = UIEdgeInsetsMake(120, 0, 0, 0);
self.myScrollView.contentOffset = CGPointMake(0, - 120);
self.myScrollView.scrollIndicatorInsets = UIEdgeInsetsMake(120, 0, 0, 0);

self.myScrollView.contentSize = CGSizeMake(pageWidth * self.contentViewControllers.count, pageHeight);

- (UIScrollView *)myScrollView{
if (!_myScrollView) {
    _myScrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
    _myScrollView.backgroundColor = [UIColor blackColor];
    _myScrollView.pagingEnabled = YES;
    _myScrollView.directionalLockEnabled = YES;
    _myScrollView.delegate = self;
    //_myScrollView.delaysContentTouches = NO;
    //_myScrollView.scrollsToTop = NO;
}

return _myScrollView;
}