Question

现在我有了这段代码：

requester.h

#ifndef REQUESTER_H
#define REQUESTER_H

#include <QtNetwork/QNetworkAccessManager>
#include <QtNetwork/QNetworkReply>
#include <QtCore/QtCore>
#include <QVector>
#include <QObject>

class Requester
{
Q_OBJECT
public:
    Requester();
    ~Requester();
    QString get_last_reply();
    void send_request();
private:
    QNetworkAccessManager *manager;
    QVector<QString> replies;
public slots:
    void get_reply(QNetworkReply *reply);
};

#endif // REQUESTER_H

requester.cpp

#include "requester.h"

Requester::Requester()
{
    manager = new QNetworkAccessManager;
}

Requester::~Requester() {
    delete manager;
}


void Requester::get_reply(QNetworkReply *reply) {
    QByteArray res = reply->readAll();
    QString data = res.data();
    replies.push_back(data);
}

QString Requester::get_last_reply() {
    QString res =  replies.back();
    replies.pop_back();
    return res;
}
void Requester::send_request() {
    QObject::connect(manager, SIGNAL(finished(QNetworkReply*)), this,     SLOT(get_reply(QNetworkReply*)));
    manager->get(QNetworkRequest(QUrl("http://google.com")));
}

这个错误：

no matching function for call to 'QObject::connect(QNetworkReply*&, const char*, Requester* const, const char*)'

出了什么问题？我曾尝试使用connect而不是QObject :: connect，但是有一个错误，即无法将QNetworkAccessmanager转换为socket。

Answer 1

问题是你没有继承QObject，所以很自然：你不能在那个类中处理插槽。

你应该写这样的东西：

requester.h

class Requester : public QObject
{
Q_OBJECT
public:
    explicit Requester(QObject *parent);
...

requester.cpp

#include "requester.h"

Requester::Requester(QObject *p)
    : QObject(p)
    , manager(new QNetworkAccessManager)
{
}
...

此外，在这种情况下，在堆上构造QNetworkAccessManager而不是堆栈几乎没有意义。您可以拥有一个QNetworkAccessManager m_networkAccessManager;没有分配，构造和删除的成员，但这只是未来的附加信息。

将qnetworkaccessmanager连接到插槽

1 个答案:

requester.h

requester.cpp