iOS之― NSRegularExpression正則分割字符串

社交化越來為社會所接受，在做社會化產品時，在回復或轉發時會@他人 展現出來，點擊@user 跳轉到該用戶的介紹頁面，這里首先要制定恰當的標簽，比如：<at href="jecky://profile/239">iJecky</at>，然后客戶端拿到文本時，要用到NSRegularExpression分割string，下面以富文本OHAttributedLabel來演示：

說明：本文中用到的contentLabel為OHAttributedLabel類型

示例：

NSString  *atstring = @"測試啊測試啊 <at href="jecky://profile/239">iJecky</at> 測試啊測試啊";

首先分割：

    NSMutableString *resultStr = [NSMutableString stringWithCapacity:0];

    NSString *pattern = @"<at href="(.*?)">(.*?)</at>";

    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern options:0 error:nil];

    NSArray *matches = [regex matchesInString:atstring options:0 range:NSMakeRange(0, atstring.length)];

    NSUInteger lastIdx = 0;

    for (NSTextCheckingResult* match in matches)

    {

        NSRange range = match.range;

        if (range.location > lastIdx)

        {

            NSString  *temp = [atstring substringWithRange:NSMakeRange(lastIdx, range.location - lastIdx)];

            [resultStr appendString:temp];

        }

        NSString *link = [atstring substringWithRange:[match rangeAtIndex:1]];

        NSString *text = [atstring substringWithRange:[match rangeAtIndex:2]];

        NSString *atName = [NSString stringWithFormat:@"@%@",text];

        [resultStr appendString:atName];

        [markDic setObject:link forKey:atName];

        lastIdx = range.location + range.length;

    }

    if (lastIdx < atstring.length)

    {

        NSString  *temp = [atstring substringFromIndex:lastIdx];

        [resultStr appendString:temp];

    }

    self.contentLabel.text = resultStr;

然后展現到contentLabel上

    NSRegularExpression* userRegex = [NSRegularExpression regularExpressionWithPattern:@"B@w+" options:0 error:nil];

    NSMutableAttributedString* mas = [self.contentLabel.attributedText mutableCopy];

    [userRegex enumerateMatchesInString:self.contentLabel.text options:0

                                  range:NSMakeRange(0,self.contentLabel.text.length)

                             usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop){

                                 NSString  *auser = [self.contentLabel.text substringWithRange:match.range];       

                                 NSString  *atlink = [markDic objectForKey:auser];

                                 if (atlink) {

                                     [mas setLink:[NSURL URLWithString:[markDic objectForKey:auser]] range:match.range]; // add it

                                 }

                             }];

    OHParagraphStyle* para = [OHParagraphStyle defaultParagraphStyle];

    para.firstLineHeadIndent = 0;

    para.headIndent = 5;

    para.tailIndent = -5;

    para.textAlignment = kCTTextAlignmentLeft;

    [mas setParagraphStyle:para];

    [OHASBasicMarkupParser processMarkupInAttributedString:mas];

    self.contentLabel.attributedText = mas;

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