插槽错误使用QNetworkAccessManager [英] slot error using QNetworkAccessManager
问题描述
我尝试实施基本的http连接 http://developer.nokia.com/community / wiki / Creating_an_HTTP_network_request_in_Qt 到Qt,但我很难实施插槽。我是一个Qt新手。
C:\Qt5\Tools\QtCreator\bin\miniHTTP\main.cpp:10:错误:请求'mTest'中的成员'Test',它是非类型'coreEng()'
mTest.Test();
// main。 cpp
#include< QCoreApplication>
#include< coreeng.h>
int main(int argc,char * argv [])
{
QCoreApplication a(argc,argv);
coreEng mTest;
mTest.Test()
return a.exec();
}
// coreeng.h
#ifndef COREENG_H
#define COREENG_H
#include< QDebug>
#include< QObject>
#include< QNetworkAccessManager>
class coreEng:public QObject
{
Q_OBJECT
public:
explicit coreEng(QObject * parent = 0);
void Test();
私有插槽:
公共插槽:
void connect();
void url();
void finishedSlot();
private:
QNetworkAccessManager * nam;
};
#endif // COREENG_H
// coreeng.cpp
#includecoreeng.h
#include< QNetworkAccessManager>
#include< QUrl>
#include< QNetworkRequest>
#include< QNetworkReply>
#include< QImageReader>
coreEng :: coreEng(QNetworkReply * parent):
QObject(parent)
{
}
void coreEng ::测试();
void coreEng :: connect(){
QObject :: connect(nam,SIGNAL(finished(QNetworkReply *)),
this,SLOT(finishedSlot(QNetworkReply *)) );
}
void coreEng :: url(){
QUrl url(http://www.forum.nokia.wiki);
QNetworkReply * reply = nam-> get(QNetworkRequest(url));
}
void coreEng :: finishedSlot(QNetworkReply * reply){
QVariant statusCodeV = reply-> attribute(QNetworkRequest :: HttpStatusCodeAttribute) ;
QVariant redirectionTargetUrl = reply-> attribute(QNetworkRequest :: RedirectionTargetAttribute);
if(reply-> error()== QNetworkReply :: NoError)
{
QImageReader imageReader(reply);
QImage pic = imageReader.read();
QByteArray bytes = reply-> readAll(); // bytes
QString string(bytes); // string
}
else
{
}
delete reply;
}
是你遇到最烦躁的解析: http://en.wikipedia.org/wiki/Most_vexing_parse
更改
coreEng mTest
到
coreEng mTest;第二个问题是你的构造函数在coreeng.cpp中有错误的签名
更改:
coreEng :: coreEng(QNetworkReply *):
QObject )
到
code> coreEng :: coreEng(QObject * parent):
QObject(parent)
I am trying to implement a basic http connection http://developer.nokia.com/community/wiki/Creating_an_HTTP_network_request_in_Qt into Qt but I have difficultly implementing the slot. I am a Qt novice.
C:\Qt5\Tools\QtCreator\bin\miniHTTP\main.cpp:10: error: request for member 'Test' in 'mTest', which is of non-class type 'coreEng()' mTest.Test();
//main.cpp
#include <QCoreApplication>
#include <coreeng.h>
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
coreEng mTest;
mTest.Test();
return a.exec();
}
//coreeng.h
#ifndef COREENG_H
#define COREENG_H
#include <QDebug>
#include <QObject>
#include <QNetworkAccessManager>
class coreEng : public QObject
{
Q_OBJECT
public:
explicit coreEng(QObject *parent = 0);
void Test();
private slots:
public slots:
void connect();
void url();
void finishedSlot();
private:
QNetworkAccessManager* nam;
};
#endif // COREENG_H
//coreeng.cpp
#include "coreeng.h"
#include <QNetworkAccessManager>
#include <QUrl>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QImageReader>
coreEng::coreEng(QNetworkReply* parent) :
QObject(parent)
{
}
void coreEng::Test();
void coreEng::connect(){
QObject::connect(nam, SIGNAL(finished(QNetworkReply*)),
this, SLOT(finishedSlot(QNetworkReply*)));
}
void coreEng::url(){
QUrl url("http://www.forum.nokia.wiki");
QNetworkReply* reply = nam->get(QNetworkRequest(url));
}
void coreEng::finishedSlot(QNetworkReply* reply){
QVariant statusCodeV = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
QVariant redirectionTargetUrl = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
if (reply->error() == QNetworkReply::NoError)
{
QImageReader imageReader(reply);
QImage pic = imageReader.read();
QByteArray bytes = reply->readAll(); // bytes
QString string(bytes); // string
}
else
{
}
delete reply;
}
One problem is you are running into the most vexing parse: http://en.wikipedia.org/wiki/Most_vexing_parse
Change
coreEng mTest();
to
coreEng mTest;
A second problem is your constructor in coreeng.cpp has the wrong signature
Change:
coreEng::coreEng(QNetworkReply*) :
QObject(parent)
to
coreEng::coreEng(QObject* parent) :
QObject(parent)
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