Question

所以我的rootViewController包含一个带有自定义UICollectionViewCell的UICollectionView。我在单元格上有一个标签，标题不应该改变，我有一个多行标签构成单元格其余部分的主体。当我启动应用程序时，它正确调用sizeToFit，顶部对齐所有内容，使其不居中。我单击其中一个单元格并转到下一个视图，然后如果单击后退按钮返回到rootViewController，它会运行viewWillAppear方法并重新加载数据，但sizeToFit不起作用，并且多行上的所有内容标签变为中心对齐。它仍然是多行，但如果只有几行，它就位于标签的中心，看起来不太好。我怎样才能保持这一点以便它是一致的。我有一个左侧菜单，将重新加载rootViewController，它将再次正确定位标签但是一旦我从secondViewController点击后退按钮，它就不再对齐了。有没有办法清除所有单元格并重新加载它们。我试过[collectionView reloadData];在viewWillAppear中它不起作用，它当前在connectionDidFinish的末尾调用，从viewWillAppear方法调用网络连接。任何帮助表示赞赏。

这是自定义UICollectionViewCell代码

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {

    }
    return self;
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
    [contentLabel setNumberOfLines:0];
    [contentLabel sizeToFit];
}

RootViewController的

-(UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:
(NSIndexPath *)indexPath
{
    NSString *cellIdentifier = @"LocationListCell";
    LocationList *cell = [cv dequeueReusableCellWithReuseIdentifier:cellIdentifier 
                                                           forIndexPath:indexPath];

    [cell.titleBar setText:[value objectAtIndex:indexPath.row]];
    NSArray *tempObject = [[NSArray alloc] initWithArray:[self getData:[key   
                                           objectAtIndex:indexPath.row]]];

    NSMutableString *tempString = [[NSMutableString alloc] init];
    for (int i = 0; i < [tempObject count]; i++)
    {
        [tempString appendString:[tempObject objectAtIndex:i]];
        [tempString appendString:@"\r"];
    }
    //[cell.contentLabel sizeToFit];
    //[cell.contentLabel setNumberOfLines:0];
    [cell.contentLabel setText:tempString];
    return cell;
}

Answer 1

将此动态UILable与此自定义方法一起使用...

只需在.m文件中添加此方法

即可

-(float) calculateHeightOfTextFromWidth:(NSString*) text: (UIFont*)withFont: (float)width :(UILineBreakMode)lineBreakMode
{
[text retain];
[withFont retain];
CGSize suggestedSize = [text sizeWithFont:withFont constrainedToSize:CGSizeMake(width, FLT_MAX) lineBreakMode:lineBreakMode];

[text release];
[withFont release];

return suggestedSize.height;
}

并像下面那样使用它。

   UILabel *yourLable = [[UILabel alloc]init];
    [yourLable setFrame:CGRectMake(110, 31, 200, 50)];        
    [yourLable setText:tempString];
    yourLable.lineBreakMode = UILineBreakModeWordWrap;
    yourLable.numberOfLines = 0;
    yourLable.font = [UIFont fontWithName:@"Helvetica" size:12];

    yourLable.frame = CGRectMake(yourLable.frame.origin.x, yourLable.frame.origin.y, 
                             200,[self calculateHeightOfTextFromWidth:yourLable.text :yourLable.font :200 :UILineBreakModeWordWrap]  ); 


    yourLable.textColor = [UIColor darkGrayColor];

     cell.contentLabel = yourLable;

希望这能帮到你......

Answer 2

尝试以下几行：

contentLabel.textAlignment = UITextAlignmentLeft;
 contentLabel.lineBreakMode = UILineBreakModeWordWrap;

Answer 3

尝试这样并在.h文件中声明标签

contentLabel = [[UILabel alloc]initWithFrame:CGRectMake(10, 49, 202, 237)];
 [contentLabel setNumberOfLines:0];
    [contentLabel sizeToFit];
  [cell.contentLabel setText:tempString];

当按下后退按钮返回rootViewController时，UILabel sizeToFit不会保留

3 个答案: