Auto. start function after cdialog was shown?

Hello,

I want to start a time intensiv function after showing a modal cdialog.
How can I do this?

Starting the function in OnInitDialog do not work because the dialog is not shown, then.

Any ideas?

tx
Ralf

If a function is "time intensiv" then create a worker thread and start it from there.
See Using Worker Threads

Hello,

the problem is not the function.
The problem is that I want to call it immediately after the dialog is shown.
But I can not call the function from OnInitDialog, because in this case, the function is called before the dialog is shown.
It is necessary, that OnInitDialog returns!

Is there a function that is called by the system when the dialog was shown?

thx
Ralf

OK, there is a well known trick to implement such a behaviour: PostMessage a user defined message (from WM_APP range or a registered message) from OnInitDialog to the dialog itself.
Then in the message handler of this message call your function (or start a thread...)

Hello Victor,

I have not tried it, but isn't there a problem:
WM_PAINT for the dialog will only processed when there is no other message in the message queue (says msdn).
But when I post my message, it will be processed first. WM_PAINT (drawing the dialog) will processed after my function is executed. But that behaviour is bad for my app.

Ralf

Quote:

---

Originally Posted by Ralf Schneider

Hello Victor,

I have not tried it, but isn't there a problem...

---

Ralf, trying it (about one or two minutes) would have been at least one order faster than typing this post and waiting for reply (more than 30 minutes!)

You could start in in another thread in OnInitDialog. Since it's in a thread, OnInitDialog will still return and the dialog still be shown.

You may want to look into handling WM_SHOW.

Another option is to set a short timer in OnInitDialog so that OnInitDialog returns, the window is displayed the timer goes off and your function gets executed.

...or can post a user-defined message from OnInitDialog.

Example

Code:

---

// MyDialog.h

class CMyDialog : public CDialog
{
    enum {WM_POSTINITDIALOG = WM_APP + 1};

// ...

    afx_msg LRESULT OnPostInitDialog(WPARAM wParam, LPARAM lParam);
};

---

Code:

---

// MyDialog.cpp

// ...

    ON_MESSAGE(CMyDialog::WM_POSTINITDIALOG, &CMyDialog::OnPostInitDialog)
END_MESSAGE_MAP()

BOOL CMyDialog::OnInitDialog()
{
    CDialog::OnInitDialog();

    // ...

    PostMessage(CMyDialog::WM_POSTINITDIALOG);
    return TRUE;
}   

LRESULT CMyDialog::OnPostInitDialog(WPARAM wParam, LPARAM lParam)
{
    // Here the dialog IS visible...
    return 0;
}

---

Hello Ovidiu,

I tried it.
But it do not work because it seems, that the OnPaint-function of CDialog was not called before OnPostInitDialog.
And that is my main problem.

I have to think about a basical different solution.

Ralf

Quote:

---

Originally Posted by Ralf Schneider

...
I have to think about a basical different solution.

Ralf

---

There is nothing more "to think".
See the post#2. :cool:

Quote:

---

Originally Posted by Ralf Schneider

I tried it.
But it do not work because it seems, that the OnPaint-function of CDialog was not called before OnPostInitDialog.
And that is my main problem.

I have to think about a basical different solution.

---

A basically different solution, though the same well known one, is setting a timer.