Question

我是QT的新手，我正在尝试连接到REST服务并获取数据。我能够成功连接到我的机器上的本地tomcat，但我找到了slot not found错误。请让我知道我可能做错了什么，我在Qt中没有那么多的专业知识，所以请耐心等待我

Person.cpp：

#include "person.h"
 #include <QNetworkRequest>
#include <QNetworkAccessManager>
#include<QObject>
#include<QDebug>
#include<QNetworkReply>

Person::Person()
{

}

Person::~Person()
{

}
void Person::addPerson (){


    QString url_str = "http://localhost:8080/";

    Person *person = new Person;
    person->setAccountStatus (true);
    person->setFirstName ("Akshay");
    person->setId (0);
    person->setPassword ("helloWorld");
    person->setUsername ("akshay@gmail.com");

    QNetworkAccessManager *manager = new QNetworkAccessManager();

    QObject object;
    object.connect(manager,SIGNAL(finished(QNetworkReply*)),SLOT(slotRequestFinished(QNetworkReply*)));
    QNetworkRequest request;
    request.setUrl (url_str);
    request.setHeader(QNetworkRequest::ContentTypeHeader,"application/json");
    QNetworkReply *reply = 0;
    manager->get(request);

}

void Person::slotRequestFinished(QNetworkReply *reply)
{
    qDebug()<<"Task finished";
}

Person.h：

#ifndef PERSON_H
#define PERSON_H
#include<QString>
#include<QObject>
#include<QNetworkReply>

class Person
{
private:
     qint32 id;
     QString username;
     QString password;
     QString firstName;
     bool accountStatus;

public:
    Person();
    ~Person();

    qint32 getId() const;
    void setId(const qint32 &value);

    QString getUsername() const;
    void setUsername(const QString &value);

    QString getPassword() const;
    void setPassword(const QString &value);

    QString getFirstName() const;
    void setFirstName(const QString &value);

    bool getAccountStatus() const;
    void setAccountStatus(bool value);
    void addPerson();

public slots:
  void slotRequestFinished(QNetworkReply *reply);


protected:

    QList<Person> listPersons();


};

#endif // PERSON_H

}

我从main.cpp调用它：

Person *person = new Person;
person->addPerson ();

错误日志：

QML debugging is enabled. Only use this in a safe environment.
QObject::connect: No such slot QObject::slotRequestFinished(QNetworkReply*) in ../CheckNet/person.cpp:81
qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method

编辑：添加QObject：

class Person : public QObject
{
    Q_OBJECT

private :
// values, getters and setters
}

当我执行上述操作时，出现以下错误：

/home/akshay/Qtprojects/CheckNet/person.cpp:57: error: undefined reference to `vtable for Person'
/home/akshay/Qtprojects/build-CheckNet-Desktop_Qt_5_4_1_GCC_64bit-Debug/person.o:-1: In function `Person::~Person()':

Answer 1

简介

通过在新创建的QObject（在您的代码段中命名为object）使用非静态成员函数QObject::connect，您实际上是在说明所提供的SLOT是您当前正在调用成员函数的对象的一部分。

QObject object;
object.connect(...);
    // ^- almost always wrong (deleteLater is the only slot in `QObject`)

通过上面的逻辑，我们可以很容易地看到你所描述的错误的原因; QObject没有相关的广告位。

解决方案

您可以在真正具有所需SLOT的对象（在您的情况下为Person）中调用三个参数的非静态QObject::connect。

<子> 示例

// .- make sure `this` belongs to an object that inherits `QObject` // v this->connect ( manager, SIGNAL(finished(QNetworkReply*)), SLOT(slotRequestFinished(QNetworkReply*)) );

另一种选择是使用QObject中的 static 成员函数，其中第三个参数表示具有SLOT的对象：

^示例

QObject::connect ( manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(slotRequestFinished(QNetworkReply*)) );

^{注意：在上面的this表示类型为Person的对象，所需的上下文位于{{1}的非静态成员函数内}，例如代码段中的Person。}

^{注意：请记住，作为发件人和接收器传递的对象必须从addPerson继承，QObject 1}}目前还没有。}

Qt：没有这样的插槽QObject :: SlotName（QNetworkReply *）

1 个答案:

简介

解决方案