QFile QDataStream QTextStream

#include <QCoreApplication>
#include <QMap>
#include <QFile>
#include <QDir>
#include <QDebug>
#include <QTextStream>
#include <QDataStream>
#include <QLinkedList>
void qDirTest()
{

    QDir dir("F:/NVIDIA");
    qDebug()  << dir.exists() ;
    qDebug() << dir.absolutePath();
    dir.cdUp();
    qDebug() << dir.absolutePath() << "
-------";

    dir.cd("NVIDIA");
    qDebug() << dir.dirName();

    QString path = "E:/test_dir";
    QDir dir_test(path);
    if(!dir_test.exists())
    {
         dir_test.mkdir(path);
    }
    dir_test.rmdir("E:/test_dir");

    // Show The Drive of files
    QString dir_path = "E:/";
    QDir dir_list(dir_path);
    foreach( QFileInfo item,dir_list.entryInfoList())
    {
        if(item.isFile())
        {
            qDebug() << item.absoluteFilePath() <<" --->is File";
        }
        if(item.isDir())
        {
            qDebug() << item.absoluteFilePath() <<" --->is Dir";
        }
    }

}

// QFile TEST

namespace QFileTextDataStream
{
    void write_text_stream(QString name)
    {
        QFile wFile(name);
        if(!wFile.open(QFile::WriteOnly | QFile::Text))   // IT's  FILE *
        {
            qDebug () << "open files error";
        }

        QTextStream stream(&wFile);
        stream << "Hello World
" << "This is jack";

        wFile.flush();
        wFile.close();
    }
    void read_text_stream(QString name)
    {

        QFile rFile(name);
        if(!rFile.open(QFile::ReadOnly | QFile::Text))   // IT's  FILE *
        {
            qDebug () << "open files error";
        }
        QTextStream in(&rFile);
        QString data = in.readAll();
        qDebug() << data;

    }

    void QFileTextTest(QString FileName)
    {
        qDebug () << "write file test";
        write_text_stream(FileName);
        qDebug() << "now Reading";
        read_text_stream(FileName);
    }

    void write_binary_stream(QString name)
    {
        QFile file(name);
        if(!file.open(QIODevice::WriteOnly))
        {
            qDebug ()  << "error";
        }
        QDataStream out(&file);
        out << QString("Houdini ") << 5;
        file.flush();
        file.close();
    }
    void read_binary_stream(QString name)
    {
        QFile file(name);
        if(!file.open(QIODevice::ReadOnly))
        {
            qDebug ()  << "error";
        }
        QDataStream read(&file);
        QString fname;
        int val;
        read >> fname >>  val;
        qDebug() << fname<<":" << val;
        file.flush();
        file.close();
    }

}


namespace DataCore
{
    void data_struction_test()
    {
        QMap<int ,QString> map;
        map.insert(10,"Houdini");
        map.insert(11,"nuke");
        map.insert(12,"maya");
        foreach (int i,map.keys())
        {
            qDebug() << map[i] ;
        }


    }


}
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
   //DirTest();
    //QFileTextDataStream::QFileTest("F:/test.txt");
    QFileTextDataStream::write_binary_stream("F:/test.binary");
    QFileTextDataStream::read_binary_stream("F:/test.binary");
    //DataCore::data_struction_test();
    return a.exec();
}

CopyFile Method 1:

// QFile And QDataStream
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QFile file("F:/dj.mp3");
    if(!file.open(QFile::ReadOnly)){
        perror("error open
");
        return 1;
    }

    QFile copy_file("F:/copytest.mp3");
    if(!copy_file.open(QFile::WriteOnly)){
        perror("error write open
");
        return 1;
    }

    QDataStream from_data(&file);
    QDataStream to_data(&copy_file);


    int buffer_size = 1024;
    char data[buffer_size];
    while(!file.atEnd())
    {
        from_data.readRawData(data,buffer_size);
        to_data.writeRawData(data,buffer_size);
    }

    file.close();
    copy_file.close();
    fprintf(stdout,"%s 
","end reading");
    return a.exec();
}

CopyFile Method 2:

QCoreApplication a(argc, argv);
    QFile file("F:/houdini-13.0.509.exe");
    if(!file.open(QFile::ReadOnly))
    {
        perror("error open
");
        return 1;
    }

    QFile copy_file("F:/copytest.exe");
    if(!copy_file.open(QFile::WriteOnly))
    {
        perror("error write open
");
        return 1;
    }

    QByteArray line;
    while(!file.atEnd())
    {
        line.clear();
        line =file.read(1000);
        copy_file.write(line);
    }

    fprintf(stdout,"%s 
","end reading");
    file.close();
    copy_file.close();
    return a.exec();

DataStream And ByteArray

#include <QCoreApplication>
#include <QDataStream>
#include <QByteArray>
#include <QDebug>
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QByteArray block;
    QDataStream stream(&block,QIODevice::WriteOnly);
    stream<<quint16(0) << QString("Houdini")<<QString("Maya");
    stream.device()->seek(0);
    stream<<quint16(15);
    qDebug() << block;


    // read back
    QDataStream stream_read(&block,QIODevice::ReadOnly);
    quint16 val;
    QString name;
    QString func;
    stream_read>>val >>name >>func;

    qDebug() << val << name <<func;



    return a.exec();
}

分割文件流:)

void get_buffer_split2(QByteArray readInArray,QList<QByteArray> &data,int buffer_size)
{

    float t = buffer_size;
    int num = ceil(float(readInArray.size())/float(t));


    for(int i=1;i<=num;i++)
    {
        QByteArray _temp =  readInArray.left(buffer_size);
        readInArray.remove(0,buffer_size);
        data.push_back(_temp);
    }
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    QByteArray readArray;
    QFile readFile("/home/gearslogy/icon.png");
    if(!readFile.open(QFile::ReadOnly))
    {
        qDebug() << "error read file";
        readFile.close();
        return 2;
    }
    readArray = readFile.readAll();

    QList<QByteArray> split_data;
    get_buffer_split2(readArray,split_data,10);

    QFile writeFile("/home/gearslogy/iconCopy.png");
    if(!writeFile.open(QFile::WriteOnly))
    {
        qDebug() << "write file error";
        writeFile.close();
        return 0;
    }

    for(int i=0;i<split_data.size();i++)
    {
        QByteArray _temp = split_data[i];
        writeFile.write(_temp);
    }
    writeFile.close();

    return a.exec();
}