Question

我正在尝试使用NSMutableAttributedString创建多行UILabel。当我将属性分配给完整的字符串时，这样可以正常工作：

UILabel *contentLabel = [[UILabel alloc] initWithFrame:CGRectMake(0,0,200,100)];
[contentLabel setLineBreakMode:NSLineBreakByWordWrapping];
[contentLabel setNumberOfLines:0];
[contentLabel setFont:[UIFont systemFontOfSize:13];

NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"hello I am a long sentence that should break over multiple lines"];
[string addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:13] range:NSMakeRange(0, [string length])];

contentLabel.attributedText = string;

但我需要的是为NSAttributedString的不同子范围应用许多属性（以加粗某些单词）。

UILabel *contentLabel = [[UILabel alloc] initWithFrame:CGRectMake(0,0,200,100)];
[contentLabel setLineBreakMode:NSLineBreakByWordWrapping];
[contentLabel setNumberOfLines:0];
[contentLabel setFont:[UIFont systemFontOfSize:13];

NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"hello I am a long sentence that should break over multiple lines"];
[string addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:13] range:NSMakeRange(3, 5)];

contentLabel.attributedText = string;

我发现如果我这样做，文本就不再在标签中的多行上呈现。它呈现为单行，在标签的框架中垂直居中。

这里有什么我想念的吗？

Answer 1

正如问题的评论中所讨论的，问题中提供的代码实际上是正常工作的，并且确实按照预期呈现了属性字符串。（问题出在我的代码中的其他地方）

Answer 2

我经常使用UITextView并为其分配一个以类似方式归属的文本：

        // creiamo textView descrizione
    UITextView *description = [[UITextView alloc] init];
    description.frame = CGRectMake(20, 453, 500, 190);

    NSDictionary *attribute1 = @{NSForegroundColorAttributeName: [UIColor blackColor],
                                     NSBackgroundColorAttributeName: [UIColor clearColor],
                                     NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue-Bold" size:22.0],
                                     };

    NSDictionary *attribute2 = @{NSForegroundColorAttributeName: [UIColor blackColor],
                                        NSBackgroundColorAttributeName: [UIColor clearColor],
                                        NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue" size:10],
                                        };

    NSDictionary *attribute3 = @{NSForegroundColorAttributeName: [UIColor blackColor],
                                           NSBackgroundColorAttributeName: [UIColor clearColor],
                                           NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue" size:14.0]
                                           };

    NSMutableAttributedString *info = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"%@ %@ %@ \n\n%@ \n     ", string1, string2 , string3, string4]];

    [info setAttributes:attribute1 range:NSMakeRange(0, ([string1 length]))];
    [info setAttributes:attribute2 range:NSMakeRange(([string1 length]),([string2 length]+[string3 length]))];
    [info setAttributes:attribute3 range:NSMakeRange(([string1 length] [string2 length]+[string3 length]), [string4 length])];

    description.attributedText = info;
    description.backgroundColor = [UIColor clearColor];
    description.editable = NO;
    description.textColor = [UIColor blackColor];
    [viewInfo addSubview:description];
    [description sizeToFit];

如何使用NSMutableAttributedString呈现多行UILabel

2 个答案: