QT FTP 查看目录代码

下面是使用QT实现的FTP查看目录的示例代码：

#include <QCoreApplication>
#include <QUrl>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QAuthenticator>
#include <QFile>
#include <QDir>
#include <QDebug>

class FTPManager : public QObject
{
    Q_OBJECT
public:
    FTPManager(QObject *parent = nullptr)
        : QObject(parent)
    {
        m_manager = new QNetworkAccessManager(this);
        connect(m_manager, &QNetworkAccessManager::authenticationRequired, this, &FTPManager::onAuthenticationRequired);
        connect(m_manager, &QNetworkAccessManager::finished, this, &FTPManager::onReplyFinished);
    }

    void list(const QUrl &url)
    {
        QNetworkRequest request(url);
        request.setAttribute(QNetworkRequest::FollowRedirectsAttribute, true);
        m_manager->get(request);
    }

signals:
    void finished(const QList<QUrlInfo> &list);

private slots:
    void onAuthenticationRequired(QNetworkReply *reply, QAuthenticator *authenticator)
    {
        // TODO: 处理FTP认证
        Q_UNUSED(reply)
        Q_UNUSED(authenticator)
    }

    void onReplyFinished(QNetworkReply *reply)
    {
        QList<QUrlInfo> list;
        if (reply->error() == QNetworkReply::NoError) {
            QTextStream in(reply);
            while (!in.atEnd()) {
                QString line = in.readLine();
                QUrlInfo info = QUrlInfo::fromEncoded(line.toUtf8());
                if (info.isValid()) {
                    list.append(info);
                }
            }
        }
        reply->deleteLater();
        emit finished(list);
    }

private:
    QNetworkAccessManager *m_manager;
};

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QUrl url("ftp://ftp.example.com");
    url.setUserName("username");
    url.setPassword("password");

    FTPManager manager;
    QObject::connect(&manager, &FTPManager::finished, [](const QList<QUrlInfo> &list){
        for (int i = 0; i < list.count(); ++i) {
            qDebug() << list[i].name();
        }
    });
    manager.list(url);

    return a.exec();
}

#include "main.moc"

该示例代码使用了`QNetworkAccessManager`类和`QUrlInfo`类来实现FTP目录的查看，其中`QNetworkAccessManager`用于发送请求和接收响应，`QUrlInfo`用于解析FTP目录列表。运行该程序，将会输出FTP服务器上的所有目录名称。需要注意的是，该示例代码中没有处理FTP认证，需要根据实际情况进行处理。