如何使用Qt只读取具有特定单词的文本文件中的一行

Question

I am reading a .txt file, I want to read only 1 line with particular word. I'm using Qt Creator .

How can I achieve this?

This is my code so far:

 QFile file("/home/a1.txt");
 if (!file.open(QFile::ReadOnly | QFile::Text)) {
     QMessageBox::warning(this,"title","file not open");
 }
 QTextStream in(&file);
 QString text = in.readAll();
 ui->plainTextEdit->setPlainText(text);
 file.close();

Answer 1

If you want to search all lines for a specific word you can do this

QFile file("/home/a1.txt");
if (!file.open(QFile::ReadOnly | QFile::Text)) {
    QMessageBox::warning(this,"title","file not open");
}
QTextStream in(&file);
QString text;
while (!in.atEnd()) {
    text = in.readLine();
    if (text.contains(/*Search her for the word you want.*/))
       break;
}
ui->plainTextEdit->setPlainText(text);
file.close();

So you loop through all lines. And in every line you check if the word exist. If yes you can stop searching and leave the loop.

I hope this helps!