Qt 文件读写

读

A：

QString
qss;

QFile qssFile(":/bar.qss");

qssFile.open(QFile::ReadOnly);

if(qssFile.isOpen())

{

qss = QLatin1String(qssFile.readAll());

this->setStyleSheet(qss);

qssFile.close();

}

B：

QFile
listfile("D:/onlinelist.txt");

if(!listfile.open(QIODevice::ReadOnly|QIODevice::Text))

{

qDebug()<<"Open failed.";

}

else

{

QTextStream textInput(&listfile);

QString lineStr;

while(!textInput.atEnd())

{

lineStr = textInput.readLine();

}

}

写

QFile f("D:/onlinelist.txt");

if(!f.open(QIODevice::WriteOnly | QIODevice::Text))

{

qDebug()<<"Open failed.";

return -1;

}

QTextStream txtOutput(&f);

QString s1("123");

quint32 n1(123);

txtOutput << s1 << endl;

txtOutput << n1 << endl;

f.close();

二进制文件的读写文件可以使用QFile类、QStream

文本文件的读写建议使用QTextStream类，它操作文件更加方便。打开文件时，需要参数指定打开文件的模式：

Constant Value Description

QIODevice::NotOpen 0x0000 The device is not open.

QIODevice::ReadOnly 0x0001 The device is open for reading.

QIODevice::WriteOnly 0x0002 The device is open for writing.

QIODevice::ReadWrite ReadOnly | WriteOnly The device is open for reading and writing.

QIODevice::Append 0x0004 The device is opened in append mode, so that all data is written to the end of the file.

QIODevice::Truncate 0x0008 If possible, the device is truncated before it is opened. All earlier contents of the device are lost.

QIODevice::Text 0x0010 When reading, the end-of-line terminators are translated to '\n'. When writing, the end-of-line terminators are translated to the local encoding, for example '\r\n' for Win32.

QIODevice::Unbuffered 0x0020 Any buffer in the device is bypassed.

QIODevice::Text在读写文本文件时使用，这样可以自动转化换行符为本地换行符。