UIScrollView 委托方法未正确调用 [英] UIScrollView delegate methods not calling properly

问题描述

为了向上和向下滚动，我需要调用两种方法，因为我使用了下面的方法.我使用 scrollview 委托方法 作为 UICollectionUIScrollView 的子视图.这是我写的代码，但滚动不容易移动，结果有时也不准确，有人可以建议吗?

In order to scroll up and down i need to call two methods for that I have used the below method .I am using scrollview delegate method for UICollection as it is the subview for UIScrollView.Here is the code that I have written but the scroll is not easily moving and the result is also not accurate for some times can any one suggest.?

- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{
    CGPoint mScrollPosition = [scrollView.panGestureRecognizer velocityInView:mCollectionView];


    if (mScrollPosition.y > 0.0f){
        NSLog(@"going down");
       //Action One
        mYearHeaderTitle--;
        [self.mCollectionView reloadData];

    }
    else if (mScrollPosition.y < 0.0f){
        NSLog(@"going up");
      //Action two
        mYearHeaderTitle++;
        [self.mCollectionView reloadData];
    }
}

推荐答案

使用 :

1. - (void)scrollViewDidScroll:(UIScrollView *)scrollView
2. - (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView

相反:

- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView

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