如何使QNetworkReply返回自定義數據？

Question

我打算使用QNetworkAccessManager通過我的移動應用程序向服務器發送HTTP服務器的請求。問題是，如何將自定義數據鏈接到每個請求？我試圖繼承QNetworkReply，但是我發現我必須實現虛擬方法close()和isSequential()，但我不知道那些應該返回的內容，所以我恐怕會打破網絡請求功能。

例如，當我的應用程序不會在日誌中的過程，它具有存儲帳戶的電子郵件地址：

class MyApp : public QObject 
{ 
    Q_OBJECT 

private: 
    QNetworkRequest    request; 
    QNetworkReply    *reply; 
    QNetworkAccessManager  *manager; 

    ... 

} 

void MyApp::do_log_in(QString email, QString password) { 
    QString s; 

    someobject.email=email; // <-- I have to store email address before sending request to server, but where do I store it? 
    s.append("http://myapp.com/do-auth.php?email="); 
    s.append(QUrl::toPercentEncoding(email)); 
    s.append("&password="); 
    s.append(QUrl::toPercentEncoding(password)); 
    connect(manager,SIGNAL(finished(QNetworkReply*)),this,SLOT(login_finished(QNetworkReply*))); 
    request.setUrl(QUrl(s)); 
    manager->get(request); 

} 

void MyApp::login_finished(QNetworkReply *rep) { 
    DepservReply *reply; 
    QString email; 
    .... 
    email= ...... // <-- I need to get the email address from QNetworkReply object somehow 
    ///my code here handling server reply 
    .... 
} 

所以，我該如何實現我的情況下，電子郵件的存儲和檢索，什麼我應該繼承哪些類，並重新實現哪些方法？

Answer 1

您可以利用每個QObject可用的動態屬性系統，並保持在該數據回覆：

// https://github.com/KubaO/stackoverflown/tree/master/questions/network-reply-tracking-40707025 
#include <QtNetwork> 

class MyCtl : public QObject 
{ 
    Q_OBJECT 
    QNetworkAccessManager manager{this}; 
    // ... 
    void reply_finished(QNetworkReply *reply); 
public: 
    MyCtl(QObject *parent = nullptr); 
    void do_log_in(const QString &email, const QString &password); 
}; 

static const char kAuthGetSalt[] = "req_auth-get-salt"; 
static const char kDoAuth[] = "req_do-auth"; 
static const char kEmail[] = "req_email"; 
static const char kPassword[] = "req_password"; 

static const auto authGetSaltUrl = QStringLiteral("https://myapp.com/auth-get-salt.php?email=%1"); 
static const auto doAuthUrl = QStringLiteral("https://myapp.com/do-auth.php?email=%1&passwordHash=%2"); 

MyCtl::MyCtl(QObject *parent) : QObject{parent} 
{ 
    connect(&manager, &QNetworkAccessManager::finished, this, &MyCtl::reply_finished); 
} 

void MyCtl::do_log_in(const QString &email, const QString &password) { 
    auto url = authGetSaltUrl.arg(email); 
    auto reply = manager.get(QNetworkRequest{url}); 
    reply->setProperty(kAuthGetSalt, true); 
    reply->setProperty(kEmail, email); 
    reply->setProperty(kPassword, password); 
} 

void MyCtl::reply_finished(QNetworkReply *reply) { 
    if (!reply->property(kAuthGetSalt).isNull()) { 
     reply->deleteLater(); // let's not leak the reply 
     if (reply->error() == QNetworkReply::NoError) { 
      auto salt = reply->readAll(); 
      auto email = reply->property(kEmail).toString(); 
      auto password = reply->property(kPassword).toString(); 
      Q_ASSERT(!password.isEmpty() && !email.isEmpty()); 
      QCryptographicHash hasher{QCryptographicHash::Sha1}; 
      hasher.addData(salt); // the server must hash the same way 
      hasher.addData("----"); 
      hasher.addData(password.toUtf8()); 
      auto hash = hasher.result().toBase64(QByteArray::Base64UrlEncoding); 
      auto url = doAuthUrl.arg(email).arg(QString::fromLatin1(hash)); 

      auto reply = manager.get(QNetworkRequest{url}); 
      reply->setProperty(kDoAuth, true); 
      reply->setProperty(kEmail, email); 
     } 
    } 
    else if (!reply->property(kDoAuth).isNull()) { 
     if (reply->error() == QNetworkReply::NoError) { 
      auto email = reply->property(kEmail).toString(); 
      // ... 
     } 
    } 
} 

通過讓編譯器檢查您使用的是有效標識符來爲屬性名稱使用常量以避免拼寫錯誤。上述

的例子在整流代碼以下關鍵的安全問題：

1. 了一個明確的連接發送的安全證書：使用https://，不http://。

2. 以明文發送密碼：相反，發送它的鹽味散列。創建帳戶時，您的服務器應爲每個帳戶生成隨機鹽。現有的帳戶可以保持不變，但只要用戶更改密碼，他們就應該獲得鹽。

還要注意QString到QUrl轉換將自動％的編碼字符串，這樣做時明確是不必要的。

Answer 2

在這種情況下email是請求的URL的一部分，所以你也可以從那裏提取它（QNetworkReply可以訪問QNetworkRequest它正在處理，請參閱QNetworkReply::request()）。

由於QNetworkReply是QObject派生類，因此您也可以存儲或多或少的任何類型的數據作爲動態屬性，請參閱QObject::setProperty()。

Answer 3

您可以繼承QNAM以獲得對其的更多控制。

network.h

class QNAMNetwork : public QNetworkAccessManager 
{ 
    Q_OBJECT 
public: 
    explicit QNAMNetwork(QObject *parent = 0); 
    ~QNAMNetwork(); 
    inline void insertUserValue(const QString & key, const QString & value){this->m_user_values.insert(key,value);} 
    inline QString getUserValue(const QString & key){return this->m_user_values.value(key);} 


signals: 
    void requestFinished(ExNetwork *, QNetworkReply *); 

private slots: 
    void _sslErrors(QNetworkReply *, const QList<QSslError> &); 
    void _finished(QNetworkReply *); 

private: 
    QMap<QString, QString>   m_user_values; 
}; 

network.cpp

QNAMNetwork::QNAMNetwork(QObject *parent):QNetworkAccessManager(parent) 
{ 
    connect(this, &QNAMNetwork::sslErrors, this, &QNAMNetwork::_sslErrors); 
    connect(this, &QNAMNetwork::finished, this, &QNAMNetwork::_finished); 
} 

QNAMNetwork::~QNAMNetwork() 
{ 
    //qDebug() << __FUNCTION__ << QString::number((long)this,16); 
} 

void QNAMNetwork::_sslErrors(QNetworkReply * reply, const QList<QSslError> & errors) 
{ 
    reply->ignoreSslErrors(errors); 
} 

void QNAMNetwork::_finished(QNetworkReply * reply) 
{ 
    emit requestFinished(this, reply); 
} 

用例：

QNAMNetwork * network = new QNAMNetwork(this); 
network->insertUserValue("email","yourmail@mail.com"); 
connect(network, SIGNAL(requestFinished(QNAMNetwork*,QNetworkReply*)), this, SLOT(requestFinished(QNAMNetwork*,QNetworkReply*))); 

QNetworkRequest req(QUrl::fromUserInput(query)); //get url 

network->get(req); 

... 

void YourClass::requestFinished(QNAMNetwork * net, QNetworkReply * rep) 
{ 
    QString email = net->getUserValue("email"); 
    net->deleteLater(); 
    rep->deleteLater(); 
}