QDialogBox GUI makes a Framebuffer copy

[CptN3m0]

Hello every one, I have a problem with QDialogBox after I implemented QThread into my application.

So what exactly is happening - after I try to open QDialogBox to open a file or save a file, my QDialogBox copy the appearance of the mainwindow with the same size and else.

[jsulm]

@CptN3m0 said in QDialogBox GUI makes a Framebuffer copy:

after I implemented QThread into my application

Can you explain (better: show code) what exactly you changed?

[CptN3m0]

@jsulm Hi,

I created a new class named "MyThread":

.h

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QThread>
#include <QString>

class MyThread : public QThread
{
    Q_OBJECT
public:
    explicit MyThread(QString s);

    void run();
signals:
    void send(int);
private:
    QString name;

};

#endif // MYTHREAD_H

.cpp

#include "mythread.h"
#include <QDebug>
#include <mainwindow.h>

MyThread::MyThread(QString s) : name(s)
{
}

void MyThread::run()
{
    for(int i = 0; i <= 1;)
    {
        emit send(i);
        sleep(1);
    }
}

wrote an signal in mainwindow

MyThread *thread= new MyThread("A");
connect(thread, SIGNAL(send(int)), this, SLOT(update(int)));
thread->start();

and just show some info in console inside of

update(int)

[jsulm]

@CptN3m0 And if you don't start the thread your app is working properly? I can't see how this thread would influence the GUI.

[CptN3m0]

@jsulm can't check right now, how my application would work without this thread.
But mayber because I check if some button in my GUI was clicked or not?

if(ui->pB_B->isChecked() == true  || ui->pB_B_2->isChecked() == true){
 // some code
}

[jsulm]

@CptN3m0 As long as you don't do this in your thread it shouldn't be a problem.

[CptN3m0]

@jsulm well.. I'm doing this in my thread.. this is also the problem, because I'm checking the state of some GUI elements?

[jsulm]

@CptN3m0 You should not access any UI related classes from other threads than GUI thread. This is not supported.

[CptN3m0]

@jsulm what should I do then, to get it working correct?

[SGaist]

Hi,

Use signals and slots to communicate your UI values to the thread.

[CptN3m0]

@SGaist Hi, can you show me a little example?

[SGaist]

Well, add two setters to your MyThread class, one for each boolean value that you want to check and connect them to your GUI.

[CptN3m0]

This post is deleted!

[CptN3m0]

I check it out without thread, doenst help. Still the same issue.

[SGaist]

Please show the complete code you are using for that part.