C++ 在 Qt 中逐行读取文本文件
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原文地址: http://stackoverflow.com/questions/5444959/
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Read a text file line by line in Qt
提问by Wassim AZIRAR
How can I read a text file line by line in Qt?
如何在 Qt 中逐行读取文本文件？
I'm looking for the Qt equivalent to:
我正在寻找相当于：
std::ifstream infile;
std::string line;
while (std::getline(infile, line))
{
...
}
回答by Sergio
Use this code:
使用此代码：
QFile inputFile(fileName);
if (inputFile.open(QIODevice::ReadOnly))
{
QTextStream in(&inputFile);
while (!in.atEnd())
{
QString line = in.readLine();
...
}
inputFile.close();
}
回答by LNJ
QFile inputFile(QString("/path/to/file"));
inputFile.open(QIODevice::ReadOnly);
if (!inputFile.isOpen())
return;
QTextStream stream(&inputFile);
QString line = stream.readLine();
while (!line.isNull()) {
/* process information */
line = stream.readLine();
};
回答by R1tschY
Since Qt 5.5 you can use QTextStream::readLineInto. It behaves similar to std::getlineand is maybe faster as QTextStream::readLine, because it reuses the string:
从 Qt 5.5 开始，您可以使用QTextStream::readLineInto. 它的行为类似于std::getline并且可能更快QTextStream::readLine，因为它重用了字符串：
QIODevice* device;
QTextStream in(&device);
QString line;
while (in.readLineInto(&line)) {
// ...
}
回答by adhityarizi
Here's the example from my code. So I will read a text from 1st line to 3rd line using readLine() and then store to array variable and print into textfield using for-loop :
这是我的代码中的示例。所以我将使用 readLine() 从第一行到第三行读取文本，然后存储到数组变量并使用 for-loop 打印到文本字段：
QFile file("file.txt");
if(!file.open(QIODevice::ReadOnly | QIODevice::Text))
return;
QTextStream in(&file);
QString line[3] = in.readLine();
for(int i=0; i<3; i++)
{
ui->textEdit->append(line[i]);
}
