UICollectionViewCell 的动态高度取决于内容

Question

嗨，我正在使用 UICollectionView，在 UICollectionViewCell 中我需要一张图片（图标）、一个标题和一些描述。我是 IOS 开发的新手，我希望 UICollectionViewCell 单元格高度取决于内容，因为可能是标题和图像将具有特定的高度，但描述具有不同的高度。谁能帮我计算描述标签的高度。我应该使用 textview 进行描述吗？

NSDictionary *service1 = [NSDictionary dictionaryWithObjectsAndKeys:
                 @"Lorem ipsum dolor sit",@"title",
                 @"Lorem ipsum dolor sit is simply dummy text Lorem ipsum dolor sit is simply dummy text Lorem ipsum dolor sit is simply dummy text Lorem ipsum dolor sit is simply dummy text Lorem ipsum dolor sit is simply dummy text",@"Description",
                 @"image1.png",@"image",
                              nil
                ];
     NSDictionary *service2 = [NSDictionary dictionaryWithObjectsAndKeys:
                @"Lorem ipsum dolor sit", @"title",
                @"Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit Lorem ipsum dolor sit",@"Description",
                 @"image2.png",@"image",
                 nil
                               ];
dataarray = [[NSMutableArray alloc] initWithObjects:service1, service2, nil];


- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *identifier = @"Cell";
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath] ;
    UIImage * img = [UIImage imageNamed:[[dataarray objectAtIndex:indexPath.row] objectForKey:@"image"]];
    UIImageView* iv = [[UIImageView alloc] initWithFrame:CGRectMake(10,10,70,70)];
    iv.image = img;

    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 90, 50, 20)];

    [titleLabel setText:[[dataarray objectAtIndex:indexPath.row] objectForKey:@"title"]];

    titleLabel.textColor = [UIColor blackColor];
    titleLabel.font = [UIFont fontWithName:@"Arial" size:8.5];
    titleLabel.backgroundColor = [UIColor clearColor];
    titleLabel.textAlignment = NSTextAlignmentLeft;

    [cell addSubview:titleLabel];


    CGRect screenRect = [[UIScreen mainScreen] bounds];
    CGFloat screenWidth = screenRect.size.width;

    UILabel *desclabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 0, screenWidth-20, 120)];

    [desclabel setText:[[dataarray objectAtIndex:indexPath.row] objectForKey:@"Description"]];

    titleLabel.textColor = [UIColor blackColor];
    titleLabel.font = [UIFont fontWithName:@"Arial" size:8.5];
    titleLabel.backgroundColor = [UIColor clearColor];
    titleLabel.textAlignment = NSTextAlignmentLeft;
    [titleLabel sizeToFit];

    [cell addSubview:titleLabel];
    [cell addSubview:desclabel];
    [cell addSubview:iv];

    return cell;

}

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout *)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{

    // Adjust cell size for orientation
    CGRect screenRect = [[UIScreen mainScreen] bounds];
    CGFloat screenWidth = screenRect.size.width;
    if (UIDeviceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation])) {

        return CGSizeMake(screenWidth-10, 170.0f);
    }
    return CGSizeMake(screenWidth-10, 190.0f);
}

Answer 1

好的，现在我明白了。需要动态计算多行 UITextView 的高度，并根据它增加默认的 UITableViewCell 行高。

尝试使用类似的东西。

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath)path
{
  // take the text value
  NSString *description = service1[@"title"];
  // initial rect value
  CGRect textFrame = CGRectMake(0,0,cellWidth,10000); // width value is enough for this operation
  UITextView *myTextView = [[UITextView alloc] initWithFrame:textFrame]; // create textview
  // set text view attributes as multiline, font, font size etc.
  myTextView.text = description;
  CGSize size = [myTextView sizeThatFits:myTextView.frame.size]; // that's all
  CGFloat height = size.height + someDefaultCellHeight;
  return height;
}

您可以在-(void)viewDidLoad 方法中创建一些私有UITextView 成员，以便在每次heightForRow 委托方法调用时不创建它。