ios - 大小与字体 : ConstrainedToSize: lineBreakMode: method is deprecated in iOS 7

Question

sizeWithFont: ConstrainedToSize: lineBreakMode: 方法在 iOS 7 中已弃用，我有点不确定如何准确处理这个问题。在互联网上做了一些研究后，我发现有一种新的方法可以处理这个问题，即:

[txt drawWithRect: options: attributes: context:]

这是我目前正在尝试运行的方法:

+ (CGSize)textSizeForText:(NSString *)txt
{
    CGFloat width = [UIScreen mainScreen].applicationFrame.size.width * 0.75f;
    CGFloat height = MAX([JSBubbleView numberOfLinesForMessage:txt],
                         [txt numberOfLines]) * [JSMessageInputView textViewLineHeight];


    return [txt sizeWithFont:[JSBubbleView font]
           constrainedToSize:CGSizeMake(width - kJSAvatarSize, height + kJSAvatarSize)
               lineBreakMode:NSLineBreakByWordWrapping];

}

但我很难将其转换为新方法。主要是 lineBreakMode: 新方法中没有。有任何想法吗？

Answer 1

在新方法中，对于换行，你必须先创建一个 NSMutableParagraphStyle Style:

  NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init]; 
  paragraphStyle.lineBreakMode = NSLineBreakByWordWrapping; 

然后通过传递所有必要的参数来简单地使用新方法

  CGRect textRect = [text boundingRectWithSize:CGSizeMake(width - kJSAvatarSize, height + kJSAvatarSize)
                                      options:NSStringDrawingUsesLineFragmentOrigin
                                   attributes:@{NSParagraphStyleAttributeName: paragraphStyle.copy}
                                      context:nil];

  return textRect.size;

如果你想让这成为潮流，你可以做到

  return ([text boundingRectWithSize:CGSizeMake(width - kJSAvatarSize, height + kJSAvatarSize)
                                      options:NSStringDrawingUsesLineFragmentOrigin
                                   attributes:@{NSParagraphStyleAttributeName: paragraphStyle.copy}
                                      context:nil]).size;

希望对你有帮助

我将在上面的答案中添加字体属性

return ([text boundingRectWithSize:CGSizeMake(width - kJSAvatarSize, height + kJSAvatarSize)
                                      options:NSStringDrawingUsesLineFragmentOrigin
                                   attributes:@{NSParagraphStyleAttributeName: paragraphStyle.copy, NSFontAttributeName:[UIFont fontWithName:@"HelveticaNeue" size:14]}
                                      context:nil]).size;