qt-文件系统

路径是否存在

QString tmpPath = "D:\\zhengjun\\remoteCom\\Win32\\Debug";
QDir dir(tmpPath);
if (dir.exists())
{
    QString fileTest = tmpPath + "\\QTTest.cfg";
    if(QFile::exists(fileTest))
        QFile::remove(fileTest);

    QFile f(fileTest);
    f.open(QIODevice::ReadWrite | QIODevice::Text);
    QTextStream ft(&f);
    ft<<param;
    f.close();
}

获取应用路径

QString strPath = QCoreApplication::applicationDirPath();
strPath += "/comBySocket.exe";

设置应用路径

QString appPath = argv[0];
QDir appDir(appPath);
QString appName = appDir.dirName();
g_appPath = appPath.left(appPath.length()-appName.length());

if (false == QDir::setCurrent(g_appPath))
{
    qDebug("set working path failed.");
}else{
    QString strLog = "set working path success:" + g_appPath;
    qDebug(strLog.toLatin1().data());
}

写二进制文件

QFile file("d:\\audio.pcm");  
file.open(QIODevice :: WriteOnly | QIODevice :: Append);  
QDataStream out(&file);  
//--向文件写入数据  
out.writeRawData((const char*)(pData+16),dwSize);
file.close();  

读二进制文件

写文本文件

#include <QtCore/QTextStream>
#include <QtCore/QFile>
#include <QtCore/QIODevice>

QString sFilePath = "C:\\test.txt";
 
QFile file(sFilePath);
//方式：Append为追加，WriteOnly，ReadOnly
if (!file.open(QIODevice::WriteOnly|QIODevice::Text)) {  
	QMessageBox::critical(NULL, "提示", "无法创建文件");
	return -1;  
}  
QTextStream out(&file);  
out<<"要写入内容"<<endl;  
out.flush();  
file.close();