Qt---QFtp上传、下载二进制文件

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFtp>
#include <QDebug>
#include <QFile>
#include <QDataStream>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QFtp *ftp = new QFtp(this);
    ftp->connectToHost("192.168.1.99", 21);
    ftp->login();
    ftp->cd("/mtp/blk/");

    //将"0x10"以二进制的方式写到"ftp://192.168.1.99/mtp/blk/2.txt"中
    int a = 0x10;
    uchar *p = (uchar *)&a;
    uchar bf[10];
    bf[0] = p[0];
    bf[1] = p[1];
    bf[2] = p[2];
    bf[3] = p[3];
    bf[4] = '\0';
    qDebug() << p[0] << p[1] << p[2] << p[3];
    ftp->put((const char*)bf, "2.txt"); 

    //将服务器上的文件下载到本地
    QFile *file;
    file = new QFile("2.txt");
    if(!file->open(QIODevice::WriteOnly))
        qDebug() << "服务器上的文件打开失败";
    ftp->get("2.txt", file);
    file->close();

    //下载到本地后打开，读出数据
    if(!file->open(QIODevice::ReadOnly))
        qDebug() << "本地文件打开失败";
    char bf1[10];
    QDataStream in(&file);
    in.readRawData((char *)&bf, 4);
    file->close();
    int aa;
    memcpy(&a, bf1, 4);
    qDebug() << aa;

    ftp->close();
}

MainWindow::~MainWindow()
{
    delete ui;
}

运行结果：

16 0 0 0
16