timer problem(timer does not work)

hi

form1.h

Code:

---

#ifndef FORM1_H
#define FORM1_H
 
#include <QString>           
 
#include <QWidget>
 
#include <QTimer>
#include <QTime>
 
 
namespace Ui {
    class Form1;
}
 
class Form1 : public QWidget
{
    Q_OBJECT
 
public:
    explicit Form1(QWidget *parent = 0);
    ~Form1();
    int i;
 
private:
    Ui::Form1 *ui;
 
 
private:               
    QTime time;
    QTimer timer;
 
public slots:
    void startTime();
    void showTime();
    void stopTime();
 
};
#endif // FORM1_H

---

form1.cpp

Code:

---

#include "form1.h"
#include "ui_form1.h"
 
 
#include <QTimer>
#include <QTime>
 
 
Form1::Form1(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Form1)
{
    ui->setupUi(this);
 
   ui->lcdNumber->setNumDigits(8);
   QTime time = QTime();
   time.setHMS(0,0,0,0);
   QTimer *timer=new QTimer(this);
   connect(timer, SIGNAL(timeout()), this, SLOT(showTime()));
   i=0;
   QString text = time.toString("hh:mm:ss");
   ui->lcdNumber->display(text);
 
 
 
}
 
Form1::~Form1()
{
    delete ui;
}
 
void Form1::startTime()
{
    timer.start();
 
}
 
void Form1::showTime()
{
    QTime newtime = QTime();
    newtime.setHMS(0,0,0,0);
    i=i+1;
    newtime=time.addSecs(i);
 
     QString text = newtime.toString("hh:mm:ss");
     ui->lcdNumber->display(text);
 
 
}
 
void Form1::stopTime()
{
   timer.stop();
}

---

timer is not working.timer is not starting

Well, you are initiate a timer in the c-tor which is not the one declared in the header file. Basic C++ failure. Read about how to initialize members correctly.

i can't understand where is the problem.please help me.

Code:

---

class Form1 : public QWidget
{
    QTimer timer;
}
 
 
Form1::Form1(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Form1)
{
   QTimer *timer=new QTimer(this);
}

---

They are not the same! You have to initialize your member correctly. Read any book about C++.

Now timer is working but cannot stop.

Code:

---

#include "form1.h"
#include "ui_form1.h"
 
 
#include <QTimer>
#include <QTime>
 
 
Form1::Form1(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Form1)
{
    ui->setupUi(this);
 
 
   time.setHMS(0,0,0,0);
   i=0;
   ui->lcdNumber->setNumDigits(8);
   QString text = time.toString("hh:mm:ss");
   ui->lcdNumber->display(text);
}
 
Form1::~Form1()
{
    delete ui;
}
 
void Form1::startTime()
{
    QTimer *timer=new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(showTime()));
    timer->start(1000);
}
 
void Form1::showTime()
{
    QTime newtime;
    i=i+1;
    newtime=time.addSecs(i);
    QString text = newtime.toString("hh:mm:ss");
    ui->lcdNumber->display(text);
 
}
 
void Form1::stopTime()
{
    QTimer *timer=new QTimer(this);
    timer->stop();
}

---

Ehm, read any book about C++! You obviously have no idea what you are doing. With that poor knowledge of C++ you won't be able to do anything with Qt since it is C++ after all. So please first learn C++.

now working...
form1.cpp

Code:

---

#include "form1.h"
#include "ui_form1.h"
 
#include <QTimer>
#include <QTime>
 
 
Form1::Form1(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Form1)
{
    ui->setupUi(this);
 
 
   time.setHMS(0,0,0,0);
   i=0;
   ui->lcdNumber->setNumDigits(8);
   QString text = time.toString("hh:mm:ss");
   ui->lcdNumber->display(text);
}
 
Form1::~Form1()
{
    delete ui;
}
 
void Form1::startTime()
{
    timer=new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(showTime()));
    timer->start(1000);
}
 
void Form1::showTime()
{
    QTime newtime;
    i=i+1;
    newtime=time.addSecs(i);
    QString text = newtime.toString("hh:mm:ss");
    ui->lcdNumber->display(text);
 
}
 
void Form1::stopTime()
{
    timer->stop();
}

---

form1.h

Code:

---

#ifndef FORM1_H
#define FORM1_H
 
#include <QString>           
 
#include <QWidget>
 
#include <QTimer>
#include <QTime>
 
 
namespace Ui {
    class Form1;
}
 
class Form1 : public QWidget
{
    Q_OBJECT
 
public:
    explicit Form1(QWidget *parent = 0);
    ~Form1();
    int i;
 
private:
    Ui::Form1 *ui;
 
 
private:               
    QTime time;
 
public:
    QTimer *timer;
 
public slots:
    void startTime();
    void showTime();
    void stopTime();
 
};
#endif // FORM1_H

---