图文混排

1.简单设置带属性的字符串

    //定义一个NSMutableAttributedString带属性的字符串
    NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:@"hello[1_1] world![哈哈][微笑]"];
    //设置属性
    [str setAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:60], NSForegroundColorAttributeName:[UIColor redColor], NSBackgroundColorAttributeName:[UIColor greenColor], NSUnderlineColorAttributeName:[UIColorblueColor], NSUnderlineStyleAttributeName:@(NSUnderlineStyleDouble)} range:NSMakeRange(0, 5)];
    //显示
    _label.attributedText = str;

2. 用表情代替带【】的文字（qq会话，微信会话）

   
   
   

    //定义正则表达式
    NSString *pattern = @"\\[[\u4E00-\u9FA5]+\\]";
    NSRegularExpression *regular = [NSRegularExpression regularExpressionWithPattern:patternoptions:NSRegularExpressionCaseInsensitive error:nil];
    
    NSString *text = @"hello[1_1] world![哈哈]";
    得到符合表达式的数组NSTextCheckingResult类型的
    NSArray *resultArray = [regular matchesInString:text options:0 range:NSMakeRange(0, text.length)];
    
    //定义一个带附件的字符串
    NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:text];
 
    for (NSTextCheckingResult *result in resultArray) {
        //位置
        NSRange range = result.range;
        //得到附件
        NSTextAttachment *attach = [[NSTextAttachment alloc] init];
        //设置附件的图片
        attach.image = [UIImage imageNamed:@"d_guzhang"];
        //得到附件生成的字符串
        NSAttributedString *imageStr = [NSAttributedString attributedStringWithAttachment:attach];
        //把文字替换成表情
        [attStr replaceCharactersInRange:range withAttributedString:imageStr];
    }
    _label.attributedText = attStr;