Can no longer build due to no matching function.

dejarked

@SGaist The code actually compiles now! Thank you, the only issue left is I've replaced the code with

            behindlogin behindlogin;
            behindlogin.show();
            connClose();


Which causes the window to open and them immediately close after

SGaist

If you have something like:

{
    behindlogin behindlogin;
    behindlogin.show();
    connClose();
} <- behindlogin is destroyed here

dejarked

@SGaist Right, so I've replaced it with

                behindlogin *behindLogin;

in the header file and then

            behindLogin =new behindlogin(this);
            behindLogin->show();

in the main cpp file but it's saying that behindlogin does not name a type?

SGaist

Is behindlogin a member variable of a class ?

dejarked

@SGaist Uh, honestly I'm not sure.. I'm very new to Qt and I've been following tutorials. Everything I've looked at makes it look like this should work but I can't figure out what I'm doing incorrectly.

JKSH

Hi,

@dejarked said:

in the main cpp file but it's saying that behindlogin does not name a type?

That means you forgot to #include the header that defines the behindlogin.

@dejarked said:

@SGaist Uh, honestly I'm not sure.. I'm very new to Qt and I've been following tutorials. Everything I've looked at makes it look like this should work but I can't figure out what I'm doing incorrectly.

Is your code exactly the same as what's in the tutorial?

dejarked

@JKSH Hey, it is exactly the same as it is in the tutorial and the header file was the first thing I checked, behindlogin.h is included in my mainwindow.h which is where I'm trying to declare it.

JKSH

@dejarked said:

@JKSH Hey, it is exactly the same as it is in the tutorial and the header file was the first thing I checked, behindlogin.h is included in my mainwindow.h which is where I'm trying to declare it.

Can you post:

The contents of your .pro file
The contents of behindlogin.h
The contents of mainwindow.h ?

dejarked

Pro:

#
# Project created by QtCreator 2015-03-25T23:10:30
#
#-------------------------------------------------

QT       += core gui sql

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = project
TEMPLATE = app


SOURCES += main.cpp\
        mainwindow.cpp \
    behindlogin.cpp \
    offlinebehind.cpp \
    savingwindow.cpp

HEADERS  += mainwindow.h \
    behindlogin.h \
    offlinebehind.h \
    savingwindow.h

FORMS    += mainwindow.ui \
    behindlogin.ui \
    offlinebehind.ui \
    savingwindow.ui

behindlogin.h

#ifndef BEHINDLOGIN_H
#define BEHINDLOGIN_H

#include <QMainWindow>
#include "mainwindow.h"

namespace Ui {
class behindlogin;
}

class behindlogin : public QMainWindow
{
    Q_OBJECT

public:
    explicit behindlogin(QWidget *parent = 0);
    ~behindlogin();

private slots:
    void on_actionExit_triggered();

    void on_actionNew_Data_triggered();

private:
    Ui::behindlogin *ui;
};

#endif // BEHINDLOGIN_H

mainwindow.h:


#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include "behindlogin.h"
#include <QMainWindow>
#include <QtSql>
#include <QtDebug>
#include <QFileInfo>


namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    QSqlDatabase mydb;
    void  connClose(){
        mydb.close();
        mydb.removeDatabase(QSqlDatabase::defaultConnection);
    }

    bool connOpen()
    {

        mydb=QSqlDatabase::addDatabase("QSQLITE");
        mydb.setDatabaseName("C:/Users/Jack/Desktop/ProjNEW/SQlite/dataset.db.sqlite");

        if(!mydb.open()){
           qDebug()<<("Disconnected..");
           return false;
        }
        else{
            qDebug()<<("Connected..");
            return true;
           }

    }

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:

    void on_LoginButton_clicked();

    void on_actionOpen_triggered();

    void on_actionExit_triggered();

private:
    Ui::MainWindow *ui;
    behindlogin *behindLogin;
};

#endif // MAINWINDOW_H

JKSH

Hmm... I can't see any mistakes in the code.

What's the full error message? Which line in which file is the error in?

dejarked

@JKSH The full message is:

In file included from /behindlogin.h
from behindlogin.cpp
behindlogin does not name a type.

and the line of code it's flagging is:


    behindlogin *behindLogin;

SGaist

Circular dependencies !

You are including mainwindow.h in behinglogin.h and behindlogin.h in mainwindow.h.

You can remove both includes: in behindlogin.h because you don't use it at all and in mainwindow.h because you can use forward declarations when declaring pointer data members. That also helps avoid including many headers to use your class.

dejarked

@SGaist Ahhh thank you so much! It's all sorted now, I've added my final bits of code and no more errors!

Thanks @SGaist for all the help and thank you @JKSH as well!

SGaist

Good !

You're welcome !

Don't forget to mark the thread as [solved] so other forum users may know a solution has been found :)