Objective-C属性字符串NSAttributedString

NSAttributedString是Objective-C中的属性字符串类，GitHub上也有很多第三方，用得较多的是TTTAttributedLabel，这里给大家介绍一下系统NSAttributedString类来实现富文本，并可实现点击事件，同时点击事件可携带参数。
因为要做点击事件，所以我们用UITextView，首先声明一个UITextView属性：

@property (nonatomic, strong) UITextView *textView;

NSAttributedString中NSFontAttributeName是用来设置文字字体的，有很多可以设置的属性，这里介绍一些常用的，其他的用到的话修改一下key-value就可以了：

//NSFontAttributeName:文字字体- (void)setAttributeCorlorAndSize{    _textView = [[UITextView alloc]initWithFrame:CGRectMake(0, 30, SCREEN_WIDTH, 100)];    _textView.editable = NO;    _textView.selectable = NO;    _textView.scrollEnabled = NO;    _textView.autoresizingMask = UIViewAutoresizingFlexibleHeight;    [self.view addSubview:_textView];    //初始化属性字符串    NSMutableAttributedString * aAttributedString = [[NSMutableAttributedString alloc] initWithString:@"富文本：文字颜色 字体大小 背景色 下划线 空心 点击事件"];    //文字颜色    [aAttributedString addAttribute:NSForegroundColorAttributeName                              value:[UIColor redColor]                              range:NSMakeRange(4, 4)];    //文字大小    [aAttributedString addAttribute:NSFontAttributeName                              value:[UIFont systemFontOfSize:18]                              range:NSMakeRange(9, 4)];    //文字背景色    [aAttributedString addAttribute:NSBackgroundColorAttributeName                              value:[UIColor blueColor]                              range:NSMakeRange(14, 3)];    //下划线  NSUnderlineColorAttributeName设置下划线颜色    [aAttributedString addAttribute:NSUnderlineStyleAttributeName                        value:[NSNumber numberWithInt:1]                        range:NSMakeRange(18, 3)];    //空心    [aAttributedString addAttribute:NSStrokeWidthAttributeName                              value:[NSNumber numberWithInt:3]                              range:NSMakeRange(22, 2)];    //点击事件携带一个NSInteger类型，值为110的参数    [aAttributedString addAttribute:@"tapID" value:[NSNumber numberWithInteger:110] range:NSMakeRange(25, 4)];    [_textView addGestureRecognizer:[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(textTapped:)]];    NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc] init];    //行间距    paragraphStyle.lineSpacing = 15.0;    [aAttributedString addAttribute:NSParagraphStyleAttributeName                             value:paragraphStyle                             range:NSMakeRange(0, aAttributedString.length)];    _textView.attributedText = aAttributedString;}

点击事件实现：

-(void)textTapped:(UITapGestureRecognizer*)recognizer{    NSLayoutManager *layoutManager = _textView.layoutManager;    CGPoint location = [recognizer locationInView:_textView];    location.x -= _textView.textContainerInset.left;    location.y -= _textView.textContainerInset.top;    NSUInteger characterIndex = [layoutManager characterIndexForPoint:location                                                      inTextContainer:_textView.textContainer                             fractionOfDistanceBetweenInsertionPoints:NULL];    if(characterIndex < _textView.textStorage.length){        NSRange range;        id number = [_textView.attributedText attribute:@"tapID" atIndex:characterIndex effectiveRange:&range];        NSNumber *value_id = number;        NSLog(@"%@", value_id);    }}

NSParagraphStyleAttributeName用来设置段落样式（字符串通过“\n”进行分段，此设置必须在lable.numberOfLines = 0时有效，value通过NSMutableParagraphStyle设置，它有以下属性）

- (void)setAttributeParagraph{    UILabel *label2 = [[UILabel alloc]initWithFrame:CGRectMake(0, 130, SCREEN_WIDTH, 200)];    label2.numberOfLines = 0;    [self.view addSubview:label2];    NSMutableAttributedString * attributedString = [[NSMutableAttributedString alloc] initWithString:@"NSParagraphStyleAttributeName　段落样式（字符串通过“\n”进行分段，此设置必须在lable.numberOfLines = 0时有效，value通过NSMutableParagraphStyle设置，它有以下属性）"];    //段落样式    NSMutableParagraphStyle * paragraphStyle = [[NSMutableParagraphStyle alloc] init];    //段落间距    paragraphStyle.paragraphSpacing = 20.0;    [attributedString addAttribute:NSParagraphStyleAttributeName                                          value:paragraphStyle                                          range:NSMakeRange(0, attributedString.length)];         label2.attributedText = attributedString;}

效果图，点击事件就不演示了，但点击“点击事件”四个字的时候，控制台打印所携带的参数110。