ios - 删除 subview 并将其添加到自定义 UITableViewCell

Question

我有一个带有不同 subview 的自定义单元格。其中之一，UIImageView，是可选的。因此可能存在单元格中不需要图像的情况。我的问题是我不知道如何删除不需要它的单元格的图像，以及如何为需要它的单元格添加图像？我知道我只应该像这样添加和删除 subview :

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

static NSString *CellIdentifier1 = @"NewsCell";

    GTNewsCustomCell *newsCell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier1];

    if(newsCell == nil){

        newsCell = [[GTNewsCustomCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier1];

       //Here i get the Image from my Array (self.newsList)
        NSString *boardImg = [[self.newsList objectAtIndex:indexPath.section] valueForKey:@"boardnoteImage"];

        //Here im checkin if an image exists
        if(boardImg == (NSString *)[NSNull null] || boardImg == nil || boardImg.length == 0){

            //If no Image exists remove the subview
            [newsCell.boardNoteImage removeFromSuperview];

        } else {

            //If an image exists, check if the subview is already added
            if(![newsCell.boardNoteImage isDescendantOfView:newsCell.contentView ]) {
                [newsCell.contentView addSubview:[newsCell.boardNoteImage];

        }
    }
}

但这不起作用，因为现在我在每个单元格上得到相同的图像......

编辑:

对不起，我忘了说我使用的 Section 每个部分只有一行，这就是我使用 indexPath.section 的原因!

我从网络服务器获取所有数据，并将所有内容放入我的数组 self.newsList 中!

编辑 2:使用此代码，我获得了正确单元格的正确图像，但是向下滚动并向上滚动后，一切都消失了:/

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

static NSString *CellIdentifier1 = @"NewsCell";

    GTNewsCustomCell *newsCell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier1];

    if(newsCell == nil){

        newsCell = [[GTNewsCustomCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier1];

    }

    NSString *boardImg = [[self.newsList objectAtIndex:indexPath.section] valueForKey:@"boardnoteImage"];

    if(boardImg == (NSString *)[NSNull null] || boardImg == nil || boardImg.length == 0){

        [newsCell.boardNoteImage removeFromSuperview];
        newsCell.boardNoteImage.image = nil;
    } else {

        if(![newsCell.boardNoteImage isDescendantOfView:newsCell.contentView ]) {

            newsCell.boardNoteImage.frame = CGRectMake(newsCell.boardNoteImage.frame.origin.x, newsCell.boardNoteImage.frame.origin.y, newsCell.boardNoteImage.frame.size.width, newsCell.boardNoteImage.frame.size.height);

            [newsCell.contentView addSubview:newsCell.boardNoteImage];

        }
    }

Answer 1

尝试这种方法 - 在 Storyboard中添加 UIImageView，您可以在需要应用逻辑时隐藏和取消隐藏。

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
   GTNewsCustomCell *cell = [tableView dequeueReusableCellWithIdentifier:@"SongCell"];
   if(cell == nil)
  {
     cell = [[CustomCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"SongCell"];
     //dont check the presence of image in this part becz it is called during creation only not on resuing
  }
  //check if image is present or not
  NSString *boardImg = [[self.newsList objectAtIndex:indexPath.row] valueForKey:@"boardnoteImage"];
   if(boardImg)
   {
      //image is present
     cell.boardNoteImage.hidden = NO;

      cell.boardNoteImage.image = boardImg;


   }
   else
   {
     cell.boardNoteImage.frame = CGRectZero;//which places a zero rect means no image
     cell.boardNoteImage.hidden = YES;

   }

 return cell;
}