1 Error + need an advice from you guys
-
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 )
-
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 :(
-
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);}@
-
Then, did you try to call qmake "Run qmake" from the "Build" menu of Qt Creator ?
-
Yes :( same problem
-
Also with a "Rebuild All" ?
@#include <QtGui> << bad habit only include what you use@
-
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.
-
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)
-
Oh , thanks man , I just like to compile it once in a while so i won't get lots of errors after finishing .
by the way what does the qt gui contain ?
-
The GUI stuff that are not widget related so you can e.g. create a GUI using only OpenGL without pulling in the widgets
-
Is learning it right now going to benefit me as a beginner ?
Also if I might ask , what's the best way to learn qt ? because I read this book and it contains lots of examples " including this one " which is not finished yet, in c++ standards I just learn the idea and then I know how to use it , but in qt it contains lost of classes and functions and I don't know how to remember them all :( , is the hardest part remembering them and knowing how to use them ?
-
Hi,
[quote author="Project try" date="1393890019"]Is learning it right now going to benefit me as a beginner ?[/quote]The classes/functions Qt GUI module are more for developers who want to implement custom graphics. I'd recommend sticking to ready-made widgets for now.
Note: In Qt 4, all widgets are part of the Qt GUI module. In Qt 5, they were moved into a separate Qt Widgets module. Keep this in mind when you read through your Qt 4 book. (Most things are still compatible between Qt 4 and Qt 5, but there are small differences to look out for)
[quote]Also if I might ask , what's the best way to learn qt ? because I read this book and it contains lots of examples " including this one " which is not finished yet, in c++ standards I just learn the idea and then I know how to use it , but in qt it contains lost of classes and functions and I don't know how to remember them all :( , is the hardest part remembering them and knowing how to use them ? [/quote]First, I recommend working inside Qt Creator, rather than the command line. Qt Creator takes care of lots of behind-the-scenes config for you, so that you can focus on coding.
Second, Qt is a very large framework/library. You can see all of Qt's modules here: http://qt-project.org/doc/qt-5/qtmodules.html -- I daresay most developers don't remember everything either. We simply remember the parts that we use most, and then search the documentation and/or ask in this forum when we want to do something that we don't know how to.
Third, I think the best way to learn Qt (and all frameworks in general) is to create little toy projects that you can interact with. The tutorials in your book should be good.
This is the official tutorial which is good too: http://doc-snapshot.qt-project.org/qt5-stable/gettingstartedqt.html It takes you through a small project from start to finish, explaining every little step. (You can ignore the XML parts though -- just focus on the C++ code)
[quote]when I remove q_object the problem goes away , not sure why.[/quote]The problem doesn't go away; it's just replaced by a different problem that shows up later. Without Q_OBJECT, your signals and slots cannot connect.
-
Thanks guys for helping ^^
@JKSH thanks man you helped a lot , I think I'll follow you advice and also check the official tutorial after finishing the first three chapters.
