Qt利用FTP下载文件

自己封装的ftpCtrl类，测试正常下载文件。

原文：默默地EEer
http://www.cnblogs.com/hebaichuanyeah/p/6083036.html

ftpCtrl.h

#ifndef FTPCTRL_H
#define FTPCTRL_H

#include <QFile>
#include <QFtp>


class FtpCtrl : public QObject
{
    Q_OBJECT

public:
    FtpCtrl(QObject *parent = 0);

    bool getFile(QString path,QString name);

    void setHost(QString host,int port=21);
    int getDone();
signals:
    void done();

private slots:
    void ftpDone(bool error);


private:
    QFtp ftp;
    QFile file;
    QString ftpHost;
    int ftpPort;
    int doneFlag;
};

#endif

ftpCtrl.cpp

#include <QtCore>
#include <QtNetwork>
#include <iostream>

#include "ftpCtrl.h"
#include <QDebug>

FtpCtrl::FtpCtrl(QObject *parent)
    : QObject(parent)
{
    connect(&ftp, SIGNAL(done(bool)), this, SLOT(ftpDone(bool)));
}

bool FtpCtrl::getFile(QString path,QString name)
{
    QDir temp;
    if(!temp.exists(path))
    {
        temp.mkpath(path);
    }
    file.setFileName(path+"/"+name);
    if (!file.open(QIODevice::WriteOnly))
    {
        qDebug() << "Error: Cannot write file "<< qPrintable(file.fileName()) << ": "<< qPrintable(file.errorString());
        return false;
    }
    ftp.connectToHost(ftpHost, ftpPort);
    ftp.login();
    doneFlag = 0;
    ftp.get(path+"/"+name, &file);
    ftp.close();
    return true;
}

void FtpCtrl::setHost(QString host,int port)
{
    ftpHost = host;
    ftpPort = port;
}


void FtpCtrl::ftpDone(bool error)
{
    if (error)
    {
        doneFlag = -1;
        std::cerr << "Error: " << qPrintable(ftp.errorString())
                  << std::endl;
    }
    else
    {
        doneFlag = 1;
        std::cerr << "File downloaded as "
                  << qPrintable(file.fileName()) << std::endl;
    }
    file.close();
    emit done();
}
int FtpCtrl::getDone()
{
    return doneFlag;
}

创建ftpCtrl对象，通过setHost函数指定ftp地址和端口（默认端口21）。

FtpCtrl ftpCtrl;
ftpCtrl.setHost("192.168.3.105");

调用getFile函数下载指定路径文件。

if(!ftpCtrl.getFile(path,name))
    return false;

调用getDone函数返回下载是否成功/完成。

int FtpThread::waitForDone()
{
    while(ftpCtrl.getDone()==0)
    {
        QThread::msleep(100);
    }
    if(ftpCtrl.getDone()>0)
        return true;
    else
        return false;
}