iOS应用故障

Question

我正在调试一个应用程序，有一个小故障。我在应用程序和互联网上查了一下，但什么也没找到。

你可以从下面找到故障

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看上去就像下面那个很短的时间间隔。

​

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我的代码：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
if (indexPath.item == 0) {
    HGOtherUserTopInformationCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForTopInfoCellProfile forIndexPath:indexPath];
    cell.user = [HGUser currentUser];
    cell.amIFollowing = false;
    cell.delegate = self;
    cell.viewController = self;
    return cell;
}else{
    if (indexPath.item % 2 != 0) {
        HGSeperatorCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForSeperatorCellProfile forIndexPath:indexPath];
        cell.backgroundColor = [UIColor lightGrayColor];
        return cell;
    }else{
        HGActivity * activity = self.profileActivities[(indexPath.item - 2) / 2];
        if ([activity.activityType isEqualToString:kActivityKeyUserPublishedResponse]) {
            // Response
            HGResponse * response = activity.response;
            if ([response.mediaType isEqualToString:@"Photo"]) {
                HGOtherUserPhotoCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForPhotoCellProfile forIndexPath:indexPath];
                cell.response = response;
                cell.indexPath = indexPath;
                cell.baseDelegate = self;
                if (userLikedResponses) {
                    if ([userLikedResponses containsObject:response.objectId]) {
                        cell.liked = true;
                    }else{
                        cell.liked = false;
                    }
                }
                cell.viewController = self;
                if (joinedChallenges) {
                    bool joined = false;
                    for (HGActivity * joinedChallengeActivity in joinedChallenges) {
                        if ([joinedChallengeActivity.challenge.objectId isEqualToString:response.challenge.objectId]) {
                            joined = true;
                            break;
                        }
                    }
                    cell.joined = joined;
                }else{
                    cell.joined = false;
                }
                return cell;
            }else if ([response.mediaType isEqualToString:@"Video"]) {
                HGOtherUserVideoCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForVideoCellProfile forIndexPath:indexPath];
                cell.response = response;
                cell.indexPath = indexPath;
                cell.baseDelegate = self;
                if (userLikedResponses) {
                    if ([userLikedResponses containsObject:response.objectId]) {
                        cell.liked = true;
                    }else{
                        cell.liked = false;
                    }
                }
                if (indexPath.item == 2) {
                    [cell playMuted];
                }
                cell.viewController = self;
                if (joinedChallenges) {
                    bool joined = false;
                    for (HGActivity * joinedChallengeActivity in joinedChallenges) {
                        if ([joinedChallengeActivity.challenge.objectId isEqualToString:response.challenge.objectId]) {
                            joined = true;
                            break;
                        }
                    }
                    cell.joined = joined;
                }else{
                    cell.joined = false;
                }
                return cell;
            }else{
                HGOtherUserMedialessCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForMedialessCellProfile forIndexPath:indexPath];
                cell.response = response;
                cell.indexPath = indexPath;
                cell.baseDelegate = self;
                if (userLikedResponses) {
                    if ([userLikedResponses containsObject:response.objectId]) {
                        cell.liked = true;
                    }else{
                        cell.liked = false;
                    }
                }
                cell.viewController = self;
                if (joinedChallenges) {
                    bool joined = false;
                    for (HGActivity * joinedChallengeActivity in joinedChallenges) {
                        if ([joinedChallengeActivity.challenge.objectId isEqualToString:response.challenge.objectId]) {
                            joined = true;
                            break;
                        }
                    }
                    cell.joined = joined;
                }else{
                    cell.joined = false;
                }
                return cell;
            }
        }else{
            // Challenge
            HGChallenge * challenge = activity.challenge;
            if ([challenge.mediaType isEqualToString:@"Photo"]) {
                HGOtherUserPhotoCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForPhotoCellProfile forIndexPath:indexPath];
                cell.challenge = challenge;
                cell.indexPath = indexPath;
                cell.baseDelegate = self;
                if (userLikedChallenges) {
                    if ([userLikedChallenges containsObject:challenge.objectId]) {
                        cell.liked = true;
                    }else{
                        cell.liked = false;
                    }
                }
                cell.viewController = self;
                if (joinedChallenges) {
                    bool joined = false;
                    for (HGActivity * joinedChallengeActivity in joinedChallenges) {
                        if ([joinedChallengeActivity.challenge.objectId isEqualToString:challenge.objectId]) {
                            joined = true;
                            break;
                        }
                    }
                    cell.joined = joined;
                }else{
                    cell.joined = false;
                }
                return cell;
            }else if ([challenge.mediaType isEqualToString:@"Video"]) {
                HGOtherUserVideoCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForVideoCellProfile forIndexPath:indexPath];
                cell.challenge = challenge;
                cell.indexPath = indexPath;
                cell.baseDelegate = self;
                if (userLikedChallenges) {
                    if ([userLikedChallenges containsObject:challenge.objectId]) {
                        cell.liked = true;
                    }else{
                        cell.liked = false;
                    }
                }
                if (indexPath.item == 2) {
                    [cell playMuted];
                }
                cell.viewController = self;
                if (joinedChallenges) {
                    bool joined = false;
                    for (HGActivity * joinedChallengeActivity in joinedChallenges) {
                        if ([joinedChallengeActivity.challenge.objectId isEqualToString:challenge.objectId]) {
                            joined = true;
                            break;
                        }
                    }
                    cell.joined = joined;
                }else{
                    cell.joined = false;
                }
                return cell;
            }else{
                HGOtherUserMedialessCell * cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifierForMedialessCellProfile forIndexPath:indexPath];
                cell.challenge = challenge;
                cell.indexPath = indexPath;
                cell.baseDelegate = self;
                if (userLikedChallenges) {
                    if ([userLikedChallenges containsObject:challenge.objectId]) {
                        cell.liked = true;
                    }else{
                        cell.liked = false;
                    }
                }
                cell.viewController = self;
                if (joinedChallenges) {
                    bool joined = false;
                    for (HGActivity * joinedChallengeActivity in joinedChallenges) {
                        if ([joinedChallengeActivity.challenge.objectId isEqualToString:challenge.objectId]) {
                            joined = true;
                            break;
                        }
                    }
                    cell.joined = joined;
                }else{
                    cell.joined = false;
                }
                return cell;
            }
        }
    }
}

Answer 1

reloadData有一个问题。旧代码如下所示

[weakSelf.collectionView reloadData];

我把它改成了这个

[weakSelf.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];

它解决了我的问题。文字中不再有小故障，而是图片上的一个小故障。但是它看起来很酷，所以我要保存它:)

Answer 2

如果您根据条件显示了许多自定义单元格，那么您必须正确地重用tableview cells.create --一个常见的UITableViewCell类(在您的示例中是例如: HGCell) --您可以根据您的需要创建多个nib(例如: HGOtherUserTopInformationCell、HGSeperatorCell.)。下面的代码显示了处理许多单元格的示例。

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *cellIdentifier = [NSString stringWithFormat:@"Cell%ld",(long)indexPath.row];

    NSString *nibName;

    if(indexPath.item == 0)
    {
        nibName = @"HGOtherUserTopInformationCell";
    }
    else
    {
        if (indexPath.item % 2 != 0)
        {
            nibName = @"HGSeperatorCell";
        }
        else
        {
            nibName = @"HGOtherUserPhotoCell";
        }
    }

    HGCell *cell = (HGCell *) [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if (cell == nil) {

        NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:nibName owner:self options:nil];

        for (id currentObject in topLevelObjects){
            if ([currentObject isKindOfClass:[UITableViewCell class]]){
                cell =  (HGCell *) currentObject;
                break;
            }
        }
    }

    //access the cell property here
    cell.backgroundColor = [UIColor lightGrayColor];

    return cell;
}