UIScrollView自動重新加載子視圖位置

Question

我有一個scrollview與subviews。 Subviews是collectionview和其他views.when用戶點擊添加按鈕在collectionview，新項目的添加到collectionview和我更新新幀爲collectionview（3項目爲1行），後我更新新幀爲另一個subviews。一切都很好。但是，當我滾動scrollview，所有subviews返回舊的位置！我不知道發生了什麼！

- (void)buttonAddPressed:(NSIndexPath *)indexPath { 
    [_productImages addObject:[UIImage imageNamed:@"4.jpg"]]; 
    [_collectionView insertItemsAtIndexPaths:@[indexPath]]; 
    double delayInSeconds = 0.5; 
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC)); 
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){ 
     float oldHeight = _collectionView.frame.size.height; 
     float newHeight = _collectionView.contentSize.height; 
     NSLog(@"new height %f",newHeight); 
     [UIView animateWithDuration:0.1 animations:^{ 
      CGRect collectionViewFrame = _collectionView.frame; 
      collectionViewFrame.size.height = newHeight; 
      _collectionView.frame = collectionViewFrame; 
     }]; 
     [self scrollViewChangeHeight:(float)(newHeight - oldHeight)]; 
    }); 
} 
- (void)scrollViewChangeHeight:(float)heightadd { 
    // thay doi chieu cao cua scrollview 
    CGSize scrollViewContentSize = _scrollView.contentSize; 
    scrollViewContentSize.height += heightadd; 
    [_scrollView setContentSize:scrollViewContentSize]; 
    // di chuyen cac phan tu ben trong 
    [UIView animateWithDuration:0.1 animations:^{ 
     for (UIView *view in _viewsUnderCollectionView) { 
      CGRect viewFrame = view.frame; 
      viewFrame.origin.y += heightadd; 
      view.frame = viewFrame; 
     } 
    }]; 
} 

Answer 1

嘗試這種解決方案：Can I use setFrame and autolayout on the same view? 我有你而這種變化的工作類似的問題。