Threads

shirisha

hi sir,
please tell me how to use threads in qt very urgent..

IamSumit

JKSH

There are many different ways to use threads in Qt. Here is an overview:

http://qt-project.org/doc/qt-5/threads-technologies.html

shirisha

hi sir..
I have seen threads in net but am not able understand hoe to use ...after all search i cme to knw writing a thred like this.

Mainwindow .cpp

QThread *thread = new QThread(this);
thread->start();
connect(thread,Signal(started()),this,Slot(SerialportRead()));

void MainWindow::SerialportRead()
{
//perform the serial port coomunication reading operation();

}

In this way i have created the thread ,but am unable to receive any response.Please help me ..

mrdebug

Hi area 51, please have a look at this project
http://kde-apps.org/content/show.php/QtComPort?content=142378
you can see how I can read and manage data from serial port.

poorBob

I really, truly recommend this site to get idea of Qt threads:
"http://mayaposch.wordpress.com/2011/11/01/how-to-really-truly-use-qthreads-the-full-explanation/":http://mayaposch.wordpress.com/2011/11/01/how-to-really-truly-use-qthreads-the-full-explanation/

best regards,
poorBob

shirisha

hi sir,

     When i use the threads , am unable to activate the widgets ...

shirisha

my code is :

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QThread>
#include <QPushButton>
#include <QDebug>
#include <QTimer>
QThread *mthread ;
QTimer *mtimer ;
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
ui->pushButton_color1->setAutoFillBackground(true);
ui->pushButton_color2->setAutoFillBackground(true);
ui->pushButton_color1->setStyleSheet("background-color : rgb(0, 255, 0)");

   mtimer = new QTimer(this);
   mthread  = new QThread(this);

   connect(mthread,SIGNAL(started()),this,SLOT(ReadData()));
   connect(mtimer,SIGNAL(timeout()),this,SLOT(TimerData()));
   mtimer->start(100);

}

void MainWindow::ReadData()
{
while(1)
{
Serial();
}
}

void MainWindow::Serial()
{

for(int i=0;i<5;i++)
    {
        qDebug()<<"BBB:" <<i;
    }
ui->pushButton_color2->setStyleSheet("background-color : rgb(0, 255, 0)");

}

void MainWindow::TimerData()
{
mtimer->stop();
mthread->start();

}
MainWindow::~MainWindow()
{
delete ui;
}

on intialy one button is geting coloured, but when i place the other button in threads that is not geting color ,please help me.

Sam

A small example of threading is provided "here":http://qt-project.org/forums/viewthread/26067

have a look at the last entry.

shirisha

Hi sir,

     how to  write a sample program on threads ..so that it should display on gui..My problem is am able to get the data on Application output window, but unable to see on gui ..please help me sir..