1 Error + need an advice from you guys

SGaist

Hi,

You are trying to add a layout which is not a QWidget.

What you must use is addLayout.

The compiler is innocent, it only compiles code. The widget "layouting" is done by the layout manager (e.g. QVBoxLayout) at run time when the widgets are created, added to it and shown.

Project try

Thanks guys ,

Project try

Hey guys , sorry about asking again , when I compile now I get 4 errors which is about linking , when I delete Q_OBJECT from the header of my class the problem goes away , but in the book it says when you use slots and signals you should include it , what do you guys think ?

Errors:

bq. finddialong.obj:-1: error: LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __cdecl Finddialong::metaObject(void)const " (?metaObject@Finddialong@@UEBAPEBUQMetaObject@@XZ)

finddialong.obj:-1: error: LNK2001: unresolved external symbol "public: virtual void * __cdecl Finddialong::qt_metacast(char const *)" (?qt_metacast@Finddialong@@UEAAPEAXPEBD@Z)

finddialong.obj:-1: error: LNK2001: unresolved external symbol "public: virtual int __cdecl Finddialong::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@Finddialong@@UEAAHW4Call@QMetaObject@@HPEAPEAX@Z)

finddialong.obj:-1: error: LNK2001: unresolved external symbol "public: static struct QMetaObject const Finddialong::staticMetaObject" (?staticMetaObject@Finddialong@@2UQMetaObject@@B)

debug\untitled10.exe:-1: error: LNK1120: 4 unresolved externals

JKSH

Hi,

[quote]in the book it says when you use slots and signals you should include it[/quote]Yes, the book is correct.

[quote]finddialong.obj:-1: error: LNK2001: unresolved external symbol “public: virtual struct QMetaObject const * __cdecl Finddialong::metaObject(void)const “ (?metaObject@Finddialong@@UEBAPEBUQMetaObject@@XZ)[/quote]To avoid this error, run qmake after you add "Q_OBJECT" to the header.

qxoz

@Project try, take a look to "qt5-book-code":https://github.com/mutse/qt5-book-code it could be useful for continue learning

Project try

@qxoz thanks , I'll check them out.

I'm sorry for posting late guys , I had to sleep + go to college :(

anyways when I installed qt it came with it a command prompt , when I opened it and wrote qmake it says you can place any variable assigement in option will be parsed and there's some option like -o file

i don't know what to do , I'm new to this , usually I just run the compiler and it just works.

Project try

Hey guys , I've gone to folder that the project is in " from command line that came with qt " and used qmake but it justs doesn't show anything , when I tried to compile it from qt creator it gives me the same error ?

maybe because I used qmake in the project ? theree's two folders when I create a new project , one is for the project files and the other is called build ....

Project try

I guess nothing worked :(

1- tried using qmake in the command line , didn't work
2- cleaned the project then ran qmake and build it and it did not work
3- used a new project and it did not work

it just gives the same error and it says nameoffile.obj not found " the same error "

SGaist

Windows is not especially user/developer friendly on the command line.

Where did you call qmake ? Did you call nmake afterwards ?

Project try

I called qmake in the command line , also in the project " when you right click " you'll find an option called " qmake " , what is nmake ? becaus when I tried it in the command line it says there's no such thing.

SGaist

nmake is the command that will read the Makefiles generated by qmake and call the compiler/linker etc…

But I am just realizing… What version of Qt is installed ? VSXXXX or MinGW ? If the later, you need to call mingw32-make after qmake

Project try

Sorry for posting late , I have the qt 5.2.1 ( msvc 2010 , 32bit) if this is what you're looking for .. the creator is 3.0.1

SGaist

Are you sure you are using the correct command line ?

Before taking too much time with it, does Qt Creator work correctly when building a default created application ? (using file -> new project -> use all defaults -> build )

Project try

Yes it works fine with the default building , it shows the main window just fine , as I said when I remove q_object the problem goes away , not sure why.

sorry for wasting your time with me :(

Project try

Let me just post the code here so you can check ^^

the interface for the class:

@#ifndef FINDDIALONG_H
#define FINDDIALONG_H
#include<QDialog>

class QCheckBox;
class QLabel;
class QLineEdit;
class QPushButton;

class Finddialong : public QDialog
{
Q_OBJECT
public:
Finddialong(QWidget *parent=0);
signals:
void findNext(const QString &str,Qt::CaseSensitivity cs);
void findPrevious(const QString &str,Qt::CaseSensitivity cs);
private slots:
void findClicked();
void enablefindButton(const QString &text);
private:
QLabel *label;
QLineEdit *lineEdit;
QCheckBox *backwardCheckBox;
QCheckBox *caseCheckBox;
QPushButton *findButton;
QPushButton *closeButton;
};

#endif // FINDDIALONG_H
@

the implement for the class:

@#include<QtGui>
#include "finddialong.h"
#include<QHBoxLayout>
#include<QVBoxLayout>
#include<QPushButton>
#include<QLabel>
#include<QLineEdit>
#include<QCheckBox>

Finddialong::Finddialong(QWidget *parent) : QDialog(parent)
{
label=new QLabel(tr("Find &what:"));
lineEdit = new QLineEdit;
label->setBuddy(lineEdit);
caseCheckBox=new QCheckBox(tr("Match &case"));
backwardCheckBox=new QCheckBox(tr("Search &backward"));
findButton=new QPushButton(tr("&Find"));
findButton->autoDefault();
findButton->setEnabled(false);
closeButton = new QPushButton(tr("close"));
connect(lineEdit,SIGNAL(textChanged(const QString &)),this,SLOT(enableFindButton(const QString &)));
connect(findButton,SIGNAL(clicked()),this,SLOT(findClicked()));
connect(closeButton,SIGNAL(clicked()),this,SLOT(close()));
QHBoxLayout *topLeftLayout=new QHBoxLayout;
topLeftLayout->addWidget(label);
topLeftLayout->addWidget(lineEdit);
QVBoxLayout *LeftLayout=new QVBoxLayout;
LeftLayout->addLayout(topLeftLayout);
LeftLayout->addWidget(backwardCheckBox);
LeftLayout->addWidget(caseCheckBox);
QVBoxLayout *rightLayout=new QVBoxLayout;
rightLayout->addWidget(findButton);
rightLayout->addWidget(closeButton);
rightLayout->addStretch();
QHBoxLayout *mainLayout=new QHBoxLayout;
mainLayout->addLayout(LeftLayout);
mainLayout->addLayout(rightLayout);
setLayout(mainLayout);

}@

SGaist

Then, did you try to call qmake "Run qmake" from the "Build" menu of Qt Creator ?

Project try

Yes :( same problem

SGaist

Also with a "Rebuild All" ?

@#include <QtGui> << bad habit only include what you use@

Project try

yes I rebuild it all , if you can try the class and see what happens pls :(

also about the qtgui in the book it says include it , but what does it do ? it says it contains two files.

SGaist

You are missing the implementation of both your slots. Once you add that you should be able to compile it.

It's called a "module include". It will include everything from the module. You don't want your compiler to go through all of that when building an application (it can be ok for a quick prototyping but that's all)