VS2013 with QT5.3.2 using Websocket and got a unresolved external symbol issue

Question

I got a problem with VS2013 and QT5.3.2. when I am using Websocket, it says unresolved external symbol with QWebSocket::sendTextMessage and other websocket functions.

I have already #include <QtWebSockets/QWebSocket> and set the QT Project Setting and checked WebKit and Network Module。

and this is the full error message I have got :

1>mainwindow.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall QWebSocket::~QWebSocket(void)" (__imp_??1QWebSocket@@UAE@XZ)，referenced in function "public: virtual __thiscall MWebSocket::~MWebSocket(void)" (??1MWebSocket@@UAE@XZ) 1>MWebSocket.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: virtual __thiscall QWebSocket::~QWebSocket(void)" (__imp_??1QWebSocket@@UAE@XZ) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall QWebSocket::QWebSocket(class QString const &,enum QWebSocketProtocol::Version,class QObject *)" (__imp_??0QWebSocket@@QAE@ABVQString@@W4Version@QWebSocketProtocol@@PAVQObject@@@Z)，referenced in function "public: __thiscall MWebSocket::MWebSocket(class QUrl const &,class QObject *)" (??0MWebSocket@@QAE@ABVQUrl@@PAVQObject@@@Z) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __int64 __thiscall QWebSocket::sendTextMessage(class QString const &)" (__imp_?sendTextMessage@QWebSocket@@QAE_JABVQString@@@Z)，referenced in function "private: void __thiscall MWebSocket::onConnected(void)" (?onConnected@MWebSocket@@AAEXXZ) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall QWebSocket::close(enum QWebSocketProtocol::CloseCode,class QString const &)" (__imp_?close@QWebSocket@@QAEXW4CloseCode@QWebSocketProtocol@@ABVQString@@@Z)，referenced in function "private: void __thiscall MWebSocket::onTextMessageReceived(class QString)" (?onTextMessageReceived@MWebSocket@@AAEXVQString@@@Z) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall QWebSocket::open(class QUrl const &)" (__imp_?open@QWebSocket@@QAEXABVQUrl@@@Z)，referenced in function "public: __thiscall MWebSocket::MWebSocket(class QUrl const &,class QObject *)" (??0MWebSocket@@QAE@ABVQUrl@@PAVQObject@@@Z) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall QWebSocket::connected(void)" (__imp_?connected@QWebSocket@@QAEXXZ)，referenced in function "public: __thiscall MWebSocket::MWebSocket(class QUrl const &,class QObject *)" (??0MWebSocket@@QAE@ABVQUrl@@PAVQObject@@@Z) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall QWebSocket::disconnected(void)" (__imp_?disconnected@QWebSocket@@QAEXXZ)，referenced in function "public: __thiscall MWebSocket::MWebSocket(class QUrl const &,class QObject *)" (??0MWebSocket@@QAE@ABVQUrl@@PAVQObject@@@Z) 1>MWebSocket.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: void __thiscall QWebSocket::textMessageReceived(class QString const &)" (__imp_?textMessageReceived@QWebSocket@@QAEXABVQString@@@Z)，referenced in function "private: void __thiscall MWebSocket::onConnected(void)" (?onConnected@MWebSocket@@AAEXXZ) 1>MWebSocket.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static struct QMetaObject const QWebSocket::staticMetaObject" (__imp_?staticMetaObject@QWebSocket@@2UQMetaObject@@B) 1>debug/\MapleUI.exe : fatal error LNK1120: 9 unresolved externals

this is the code for Websocket:

//HEADER
#pragma once
#include "global.h"


class MWebSocket : public QObject
{
    Q_OBJECT
public:
    explicit MWebSocket(const QUrl &url, QObject *parent = Q_NULLPTR);

Q_SIGNALS:
    void closed();

    private Q_SLOTS:
    void onConnected();
    void onTextMessageReceived(QString message);

private:
    QWebSocket m_webSocket;
    QUrl m_url;
};



//CPP

#include "global.h"
#include "MWebSocket.h"

QT_USE_NAMESPACE

//! [constructor]
MWebSocket::MWebSocket(const QUrl &url, QObject *parent) :
QObject(parent),
m_url(url)
{
    connect(&m_webSocket, &QWebSocket::connected, this, &MWebSocket::onConnected);
    connect(&m_webSocket, &QWebSocket::disconnected, this, &MWebSocket::closed);
    m_webSocket.open(QUrl(url));
}
//! [constructor]

//! [onConnected]
void MWebSocket::onConnected()
{
    qDebug() << "WebSocket connected";
    connect(&m_webSocket, &QWebSocket::textMessageReceived,
        this, &MWebSocket::onTextMessageReceived);
    m_webSocket.sendTextMessage(QStringLiteral("H2ello, world!"));
}
//! [onConnected]

//! [onTextMessageReceived]
void MWebSocket::onTextMessageReceived(QString message)
{
    qDebug() << "Message received:" << message;
    m_webSocket.close();
}
//! [onTextMessageReceived]

anyone have idea about how to solve this problem? thanks

possible duplicate of What is an undefined reference/unresolved external symbol error and how do I fix it? — wimh
I know what is a unresolved external symbol but the problem is how to fix it. — Elyse
There are several things that can be wrong. The linked question links to the most common causes. To be able to solve your specific issue, you need to supply more information. As the error is a linker error, we need to know the linker settings you use. Are you using a release or a debug build? Are you linking using the static or dynamic QT library? Where is the library stored on your pc, and which library search path do you use? — wimh
@Elyse The linked question has "and how do I fix it" in its title. — sashoalm

Elyse Elyse · Accepted Answer · 2015-02-16T02:17:17

Just find out that add Qt5WebSocketsd.lib to the project will fix the problem. I dont know why this need to be manually, cuz before when I using other libs QT5 plugin will add them automate

VS2013 with QT5.3.2 using Websocket and got a unresolved external symbol issue

2 Answers