Previous frame inner to this frame(corrupt stack?)

I am building a c/s system,but now I am runing into the trouble as title.
when client process receive a message from server process,it show a modeless dialog,and when user click close button, it hide the dialog.

at first everything is ok,and then the client process is crashed. gdb shows
the error as title.


below is my way how to realize this.


class ApplicationWindow:: public QMainWindow
{
....
protected:

CControlDlg m_controlDlg; //inherit from QDialog,and I pass this to it as it's parent window in ApplicationWindow's Construct function
}


display the dialog:
ApplicationWindow::showControlDlg()
{
m_control.show()
}

hide the dialog:

CControlDlg::closeEvent(QCloseEvent* e)
{
this->hide();
}

thanks anyone who can give me some idea!

Where actually you have crash?
In calling hide() method?

Quote:

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Originally Posted by zlatko

Where actually you have crash?
In calling hide() method?

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In calling show() method. :mad:

Hm then show ApplicationWindow's Construct function

Code:

---

CControlDlg::closeEvent(QCloseEvent* e)
{
this->hide();
}

---

Won't it make an infinite loop?

Quote:

---

Originally Posted by zlatko

Hm then show ApplicationWindow's Construct function

---

ApplicationWindow::ApplicationWindow()
: QMainWindow( 0, "HMI", estructiveClose|Qt::WStyle_Customize) ,m_controlExecDlg(this)

Quote:

---

Originally Posted by wysota

Code:

---

CControlDlg::closeEvent(QCloseEvent* e)
{
this->hide();
}

---

Won't it make an infinite loop?

---

it will not,i tested as below:
CControlDlg::closeEvent(QCloseEvent* e)
{
Q_ASSERT(FALSE),
this->hide();
}

Q_ASSERT(FALSE) only execute once.

...,m_controlExecDlg(this) what is this? You try init your dialog as app window :eek:

Try next code

Code:

---

class ApplicationWindow:: public QMainWindow
{
....
protected:
CControlDlg *m_controlDlg; //inherit from QDialog,and I pass this to it as it's parent window in ApplicationWindow's Construct function
}
 
ApplicationWindow::ApplicationWindow(): QMainWindow( 0, "HMI", estructiveClose|Qt::WStyle_Customize)
{
  m_controlDlg = new CControlDlg(this);
}

---

Quote:

---

Originally Posted by zlatko

...,m_controlExecDlg(this) what is this? You try init your dialog as app window :eek:

Try next code

Code:

---

class ApplicationWindow:: public QMainWindow
{
....
protected:
CControlDlg *m_controlDlg; //inherit from QDialog,and I pass this to it as it's parent window in ApplicationWindow's Construct function
}
 
ApplicationWindow::ApplicationWindow(): QMainWindow( 0, "HMI", estructiveClose|Qt::WStyle_Customize)
{
  m_controlDlg = new CControlDlg(this);
}

---

---

It still does not work.:mad:

by the way,I pass ApplicationWindow's pointer to a QThread object, and in QThread::run() calls ApplicationWindow::ShowControlDlg().

and what is the result? :)

1. Try to clean your object code (make clean) and build it again.
2. Don't access GUI functions from within threads. It's forbidden :)

Quote:

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Originally Posted by zlatko

and what is the result? :)

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result is can show dialog successful serval times .

Quote:

---

Originally Posted by wysota

1. Try to clean your object code (make clean) and build it again.
2. Don't access GUI functions from within threads. It's forbidden :)

---

even hide() and show()?I can do it in MFC.

Quote:

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Originally Posted by coralbird

even hide() and show()?

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Yes.

Quote:

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I can do it in MFC.

---

This is not MFC. GUI operations are not thread safe (especially in Qt3). Use custom events to post a proper event to the main thread instead.
In your case this is probably as simple as

Code:

---

QApplication::postEvent(mywindow, new QShowEvent());

---

.

BTW. Does it make sense to issue "hide()" from within closeEvent? What do you need it for? close event hides the widget by itself... Just remember to call its base class implementation.

Quote:

---

Originally Posted by wysota

GUI operations are not thread safe (especially in Qt3). Use custom events to post a proper event to the main thread instead.
In your case this is probably as simple as

Code:

---

QApplication::postEvent(mywindow, new QShowEvent());

---

.

---

wysota tell me the key.I have tried signal/slot ,and it does not work too.

Quote:

---

Originally Posted by wysota

BTW. Does it make sense to issue "hide()" from within closeEvent? What do you need it for? close event hides the widget by itself... Just remember to call its base class implementation.

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I want the dialog is valid all along, maybe I make a mistake here.:p


Great thanks to wysota and zlatko!:rolleyes: :D

You should probably read this:
http://doc.trolltech.com/3.3/threads.html

Note: You can't use signals across threads in Qt3. It's possible in Qt4, though.

Quote:

---

Originally Posted by wysota

You should probably read this:
http://doc.trolltech.com/3.3/threads.html

Note: You can't use signals across threads in Qt3. It's possible in Qt4, though.

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sure ,it's is very important.and now i am reading it.