ScrollPlayVideo

核心代码

- (void)filterShouldPlayCellWithScrollDirection:(BOOL)isScrollDownward
{
    //顶部
    if (self.tableView.contentOffset.y<=0) {
        //其他的已经暂停播放
        if (self.lastOrCurrentPlayIndex==-1) {
            [self playVideoWithShouldToPlayIndex:0];
        }else{
            //第一个正在播放
            if (self.lastOrCurrentPlayIndex==0) {
                return;
            }
            //其他的没有暂停播放,先暂停其他的再播放第一个
            [self stopVideoWithShouldToStopIndex:self.lastOrCurrentPlayIndex];
            [self playVideoWithShouldToPlayIndex:0];
        }
        return;
    }
    
    //底部
    if (self.tableView.contentOffset.y+self.tableView.frame.size.height>=self.tableView.contentSize.height) {
        //其他的已经暂停播放
        if (self.lastOrCurrentPlayIndex==-1) {
            [self playVideoWithShouldToPlayIndex:self.dataArray.count-1];
        }else{
            //最后一个正在播放
            if (self.lastOrCurrentPlayIndex==self.dataArray.count-1) {
                return;
            }
            //其他的没有暂停播放,先暂停其他的再播放最后一个
            [self stopVideoWithShouldToStopIndex:self.lastOrCurrentPlayIndex];
            [self playVideoWithShouldToPlayIndex:self.dataArray.count-1];
        }
        return;
    }
    
    //中部(找出可见cell中最合适的一个进行播放)
    NSArray *cellsArray = [self.tableView visibleCells];
    NSArray *newArray = nil;
    if (!isScrollDownward) {
        newArray = [cellsArray reverseObjectEnumerator].allObjects;
    }else{
        newArray = cellsArray;
    }
    [newArray enumerateObjectsUsingBlock:^(ScrollPlayVideoCell *cell, NSUInteger idx, BOOL * _Nonnull stop) {
        NSLog(@"%ld",(long)cell.row);

        CGRect rect = [cell.videoFirstImageView convertRect:cell.videoFirstImageView.bounds toView:self];
        CGFloat topSpacing = rect.origin.y;
        CGFloat bottomSpacing = self.frame.size.height-rect.origin.y-rect.size.height;
        if (topSpacing>=-rect.size.height/3&&bottomSpacing>=-rect.size.height/3) {
            if (self.lastOrCurrentPlayIndex==-1) {
                if (self.lastOrCurrentPlayIndex!=cell.row) {
                    [cell shouldToPlay];
                    self.lastOrCurrentPlayIndex = cell.row;
                }
            }
            *stop = YES;
        }
    }];
}

调用时机:滚动停止的时候;

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    //停止的时候找出最合适的播放
    [self filterShouldPlayCellWithScrollDirection:self.isScrollDownward];
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
     //停止的时候找出最合适的播放
    [self filterShouldPlayCellWithScrollDirection:self.isScrollDownward];
}