How to display an LCD with a counter

[rookee]

Hello All,

I'm learning Qt using C++, a beginner. Trying to create LCD that starts counting from 0(zero) after execution, I want to incorporate a stop button to stop the counting when it is pressed and also want to incorporate a slider to increase or decrease the speed of counter. I want to use programming instead of UI/drag and drop functionality. This is just a start up I haven't included stop and slider yet. Can someone please guide me through this. Please!!!. Thanks in advance.

Code in my LCD3.h


#ifndef LCD3_H
#define LCD3_H
#include <QApplication>
#include <QLCDNumber>
#include <QWidget>

class ClassA: public QWidget
{
Q_OBJECT

public:
ClassA():
number(0)
{};
~ ClassA(){};

void mylcd(ClassA *window)
{
QWidget *centralWidget = new QWidget(window);
LCD = new QLCDNumber(centralWidget);
window ->setCentralWidget(centralWidget);
window->show();
LCD->display(number ++);
}
public slots:
void setNumber()
{
if(number>=51)
{
timer->stop();
}
else
{
LCD->display(number++);
}
}
public:
QLCDNumber *LCD;
int number;

};

#endif // LCD3_H






Code in my main.cpp file


#include <QApplication>
#include "LCD3.h"
#include <QLCDNumber>


int main(int argc, char *argv[])
{
QApplication a(argc, argv);

ClassA *window = new Test();
window->setWindowTitle(QString::fromUtf8("LCD Display"));
window->resize(300,300);

ClassA win;
win.mylcd(window);

return a.exec();
};



Is there a way that we can run the program in debug mode. Executing the code line by line and see what's happening on each line.



Here are the errors I get when I execute it.

/Qt Practice/LCD3/LCD3/LCD3.h:-1: In member function 'void ClassA::mylcd(ClassA*)':
/Qt Practice/LCD3/LCD3/LCD3.h:24: error: 'class ClassA' has no member named 'setCentralWidget'
/Qt Practice/LCD3/LCD3/LCD3.h:-1: In member function 'void ClassA::setNumber()':
/Qt Practice/LCD3/LCD3/LCD3.h:33: error: 'timer' was not declared in this scope
/Qt Practice/LCD3/LCD3/main.cpp:-1: In function 'int main(int, char**)':
/Qt Practice/LCD3/LCD3/main.cpp:10: error: expected type-specifier before 'Test'
/Qt Practice/LCD3/LCD3/main.cpp:10: error: cannot convert 'int*' to 'ClassA*' in initialization
/Qt Practice/LCD3/LCD3/main.cpp:10: error: expected ',' or ';' before 'Test'

[west]

Please

write code like this text

[anda_skoa]

/Qt Practice/LCD3/LCD3/LCD3.h:-1: In member function 'void ClassA::mylcd(ClassA*)':
/Qt Practice/LCD3/LCD3/LCD3.h:24: error: 'class ClassA' has no member named 'setCentralWidget'

That means your class "ClassA" does not have a method called "setCentralWidget".
It indeed doesn't but you try to use it.



/Qt Practice/LCD3/LCD3/LCD3.h:-1: In member function 'void ClassA::setNumber()':
/Qt Practice/LCD3/LCD3/LCD3.h:33: error: 'timer' was not declared in this scope

This means your class "ClassA" does not have a member variable called "timer".
It indeed doesn't but you try to use it.



/Qt Practice/LCD3/LCD3/main.cpp:-1: In function 'int main(int, char**)':
/Qt Practice/LCD3/LCD3/main.cpp:10: error: expected type-specifier before 'Test'

Means the type "Test" is not know.
Indeed you don't have such a class, your class is called "ClassA"



/Qt Practice/LCD3/LCD3/main.cpp:10: error: cannot convert 'int*' to 'ClassA*' in initialization
/Qt Practice/LCD3/LCD3/main.cpp:10: error: expected ',' or ';' before 'Test'
These are just follow-up errors because of the one before, they will go away once you fixed the other one.

Cheers,
_