qt文件读写，打开一个文件向另一个文件里写

    QTime time;
    time.start();
    int size = 4096;
    QFile file(Path);
    file.open(QIODevice::ReadOnly);
    float filesize = file.size() - 4096;
    if(filesize <= 0)
    {
        plan = 100;
        file.close();
        return true;
    }

    //_______________________________________________________________________________________________________________

    QDataStream filein(&file);
    QByteArray filedata;
    filedata.resize(4096);
    int filereadsize = filein.readRawData(filedata.data(), 4096);
    file.seek(0);
    if(filereadsize != 4096)
    {
        return false;
    }
    ecry_header pHeader;
    memcpy(&pHeader, filedata.data(), sizeof(struct ecry_header));

    //_______________________________________________________________________________________________________________

    QDataStream in(&file);
    QByteArray data;
    data.resize(size);
    QFile writefile;
    QString name = Path + QString(".tmp");
    writefile.setFileName(name);
    writefile.open(QIODevice::WriteOnly);
    chmod(name.toStdString().c_str(), 0666);    //0000
    char* pbuf = new char[4096];
    int readsize = in.readRawData(data.data(), size);
    if(readsize != 4096)
    {
        file.close();
        writefile.close();
        plan = 100;        QFile::remove(name);
        return false;
    }
    switch (type)
    {

    case FileHeader::TEST_1: case FileHeader::TEST_2:
    {
        qDebug("test1");
        int flag = (type == FileHeader::TEST_1) ? 0x01 : 0x00;
        while(!in.atEnd())
        {
            if(is_close)
            {
                file.close();
                writefile.close();
                plan = 100;
                QFile::remove(name);
                return true;
            }
            int readsize = in.readRawData(data.data(), size);
            long lResult = -1;
            memset(pbuf, 0, 4096);
            Mutex_work.lock();
            lResult = DecryptPrivate(2, data.data(), readsize, pbuf,TRUE);
            Mutex_work.unlock();
            if(lResult == false)
            {
                file.close();
                writefile.close();
                plan = 100;
                QFile::remove(name);
                return false;
            }
            if(writefile.write(pbuf, readsize) != readsize)
            {
                file.close();
                writefile.close();
                plan = 100;
                return false;
            }
            plan = 100 * (writefile.size() / filesize);
        }
        //success
        plan = 100;
    }
    break;

    default:
    {
        while(!in.atEnd())
        {
            if(is_close)
            {
                file.close();
                writefile.close();
                plan = 100;
                QFile::remove(name);
                return true;
            }
            int readsize = in.readRawData(data.data(), size);
            long lResult = -1;
            memset(pbuf, 0, 4096);
            Mutex_work.lock();
            lResult = DecryptPrivate(1, data.data(), readsize, pbuf,FALSE);
            Mutex_work.unlock();
            if(lResult == false)
            {
                file.close();
                writefile.close();
                plan = 100;
                QFile::remove(name);
                return false;
            }
            if(writefile.write(pbuf, readsize) != readsize)
            {
                file.close();
                writefile.close();
                plan = 100;
                return false;
            }
            plan = 100 * (writefile.size() / filesize);
        }
	 //success 
        plan = 100;
    }
        break;
    }

    file.close();
    writefile.close();

    m_removePath(Path){
    QString name = Path + QString(".tmp");
    QFile::remove(Ppath;

    chmod(decodeFileName.toStdString().c_str(), 0777);
    }
    delete[] pbuf;
    float s = time.elapsed()/(float)1000.00f;
    float m = filesize / 1048576.00f;
    decryptTime = s;
    qDebug() << "filepath:" << Path << " size:" << m << "m" << " time:" << s << " speed:" << m / s << "m/s";
    return true;