相关疑难解决方法(0)

我有一个UITableView与不同高度的单元格,我需要知道它们何时完全可见.

目前,我循环遍历可见单元格列表中的每个单元格,以检查每次滚动视图时它是否完全可见.这是最好的方法吗？

这是我的代码:

- (void)scrollViewDidScroll:(UIScrollView *)aScrollView {

    CGPoint offset = aScrollView.contentOffset;
    CGRect bounds = aScrollView.bounds;    
    NSArray* cells = myTableView.visibleCells;

    for (MyCustomUITableViewCell* cell in cells) {

        if (cell.frame.origin.y > offset.y &&
            cell.frame.origin.y + cell.frame.size.height < offset.y + bounds.size.height) {

            [cell notifyCompletelyVisible];
        }
        else {

            [cell notifyNotCompletelyVisible];
        }
    }
}

编辑:

请注意* - (NSArray )visibleCells返回可见单元格,这些单元格完全可见且部分可见.

编辑2:

这是在结合lnafziger和Vadim Yelagin的解决方案后的修订代码:

- (void)scrollViewDidScroll:(UIScrollView *)aScrollView {
    NSArray* cells = myTableView.visibleCells;
    NSArray* indexPaths = myTableView.indexPathsForVisibleRows;

    NSUInteger cellCount = [cells count]; …

我正在播放视频UITableViewCell.为此,我使用以下代码:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *VideoCellIdentifier = @"VideoCell";

    NSDictionary *_response_data = [self.response objectAtIndex:indexPath.row];

    VideoCustomCell *cell = (VideoCustomCell *) [tableView dequeueReusableCellWithIdentifier:VideoCellIdentifier];

    if (cell == nil) {
        NSArray *topLevelObjects;
        topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"VideoCustomCell" owner:self options:nil];
        for (id currentObject in topLevelObjects){
            if ([currentObject isKindOfClass:[UITableViewCell class]]){
                cell =  (VideoCustomCell *) currentObject;
                cell.delegate  = self;
                break;
            }
        }
    }

    avPlayer = [[AVPlayer playerWithURL:[NSURL URLWithString:[_response_data valueForKey:@"media_id"]]] retain];
    avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:avPlayer];
    avPlayerLayer.frame = cell.video_player_view.layer.bounds;
    avPlayerLayer.videoGravity = AVLayerVideoGravityResize;
    [cell.video_player_view.layer …

我有一个包含视频URL的数组,我想在UITableviewcell完全可见时播放这些视频.

我试过这个

- (void)scrollViewDidScroll:(UIScrollView *)aScrollView 
{
    NSArray* cells = homeTabl.visibleCells;

    for (HomeCell* cell in cells) 
    {
        if (cell.frame.origin.y > offset.y &&
        cell.frame.origin.y + cell.frame.size.height < offset.y + bounds.size.height)
        {
            NSIndexPath *path = [homeTabl indexPathForCell:cell] ;
            index = path.row;
            fullvisible = YES;
            [homeTabl reloadData];
        }
        else
        {
            fullvisible = NO;
        }
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
     if (fullvisible) 
     {
          NSURL *url = [NSURL URLWithString:[[responsearray objectAtIndex:indexPath.row]valueForKey:@"feed_video"]];

          cell.videoItem = [AVPlayerItem playerItemWithURL:url];
          cell.videoPlayer = [AVPlayer playerWithPlayerItem:cell.videoItem];
          cell.avLayer = [AVPlayerLayer playerLayerWithPlayer:cell.videoPlayer]; …