Signal and Slots

[waynew]

I'm trying to set up a class with a signal, but it fails to compile.

#ifndef CONTROLDB_H
#define CONTROLDB_H
 
#include <QString>
 
class ControlDB:public QObject
{
   public:
    ControlDB();
    void ControlDB::makeControlDB();
    void ControlDB::setLastLog(QString);
    void ControlDB::setOper(QString);
    QString ControlDB::getLastLog();
    QString ControlDB::getOper();
 
    signals:
    void valueChanged(QString);
};
 
#endif // CONTROLDB_H

#ifndef CONTROLDB_H
#define CONTROLDB_H

#include <QString>

class ControlDB:public QObject
{
   public:
    ControlDB();
    void ControlDB::makeControlDB();
    void ControlDB::setLastLog(QString);
    void ControlDB::setOper(QString);
    QString ControlDB::getLastLog();
    QString ControlDB::getOper();

    signals:
    void valueChanged(QString);
};

#endif // CONTROLDB_H

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Here is the error:
error: expected class-name before '{' token

What am I doing wrong here?

[positive_4_life]

AFAIK, you should try including the Q_OBJECT, and see if that helps:

#ifndef CONTROLDB_H
#define CONTROLDB_H
 
#include <QString>
 
class ControlDB:public QObject
{
   Q_OBJECT
 
   public:
    ControlDB();
    void makeControlDB();
    void setLastLog(QString);
    void setOper(QString);
    QString getLastLog();
    QString getOper();
 
    signals:
    void valueChanged(QString);
};
 
#endif // CONTROLDB_H

#ifndef CONTROLDB_H
#define CONTROLDB_H
 
#include <QString>
 
class ControlDB:public QObject
{
   Q_OBJECT

   public:
    ControlDB();
    void makeControlDB();
    void setLastLog(QString);
    void setOper(QString);
    QString getLastLog();
    QString getOper();
 
    signals:
    void valueChanged(QString);
};
 
#endif // CONTROLDB_H

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I don't particularly see the point in placing the ControlDB:: for your member functions when it is already implied they belong to the ControlDB class.

[waynew]

Ok positive_4_life. I have changed the code to this:

#ifndef CONTROLDB_H
#define CONTROLDB_H
 
#include <QString>
 
class ControlDB:public QObject
{
   Q_OBJECT
 
   public:
    ControlDB();
    void makeControlDB();
    void setLastLog(QString);
    void setOper(QString);
    QString getLastLog();
    QString getOper();
 
    //signals:
    //void valueChanged(QString);
};
 
#endif // CONTROLDB_H

#ifndef CONTROLDB_H
#define CONTROLDB_H

#include <QString>

class ControlDB:public QObject
{
   Q_OBJECT

   public:
    ControlDB();
    void makeControlDB();
    void setLastLog(QString);
    void setOper(QString);
    QString getLastLog();
    QString getOper();

    //signals:
    //void valueChanged(QString);
};

#endif // CONTROLDB_H

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Now I still get this error:
controldb.h:7: error: expected class-name before '{' token

I can't see anything wrong with it.

[ChrisW67]

You might want to #include a definition for QObject because QString doesn't:

#include <QObject>

#include <QObject>

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