如何在字符串中替换QRegExp? [英] How to replace QRegExp in a string?

问题描述

我有一个字符串.例如:

I have a string. For example:

QString myString = "Today is Tuesday";

要求是:当用户键入字符串时，如果该字符串包含在myString中，则myString中的该部分应为粗体且不区分大小写(Qt::CaseInsensitive)，但格式为应该保留(大写字母应为大写，小写字母应为小写).

The requirement is: when user types a string, if that string is contained in myString, then that part in the myString should be bold, and case insensitive (Qt::CaseInsensitive), but the format of myString should remain (upper case characters should be upper case and lower case characters should be lower case).

例如:

• 用户类型:tu->今天是 Tu 星期几
• 用户类型:ES->今天是Tu es 天
• 用户类型:aY-> Tod ay 是Tuesd ay

• user types: tu -> Today is Tuesday
• user types: ES -> Today is Tuesday
• user types: aY -> Today is Tuesday

这是我的功能:

void myClass::setBoldForMatching( const QString &p_text )
{
  QRegExp regExp( p_text, Qt::CaseInsensitive, QRegExp::RegExp );
  if ( !p_text.isEmpty() )
  {       
    if ( myString.contains( regExp ) )
    {
      myString = myString.replace( p_text, QString( "<b>" + p_text + "</b>" ), Qt::CaseInsensitive );
    }
  }
}

此功能有误，因为

用户类型t-> t 今天是 t 星期二.

user types t -> today is tuesday.

我需要的是 T ，今天是 T 星期二

What I need is Today is Tuesday

我应该如何更新我的功能?

How should I update my function?

推荐答案

我们可以使用接受QRexExp的其他QString::replace()来替换所有出现的内容.这样做的关键是我们需要一个捕获组，以便使用后向引用(\1)来替换替换中的原始文本:

We can use a different QString::replace(), which accepts a QRexExp, to substitute all occurrences. The key to this is that we need a capture group in order to replace the original text in the substitution, using a back-reference (\1):

#include <QRegExp>

QString setBoldForMatching(QString haystack, const QString& needle)
{
    if (needle.isEmpty()) return haystack;
    const QRegExp re{"("+QRegExp::escape(needle)+")", Qt::CaseInsensitive};
    return haystack.replace(re, "<b>\\1</b>");
}

演示

#include <QDebug>
int main()
{
    qInfo() << setBoldForMatching("THIS DAY (today) is Tuesday.", "Day");
}

这个 DAY (到 day )是星期二 day .

THIS DAY (today) is Tuesday.

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