QFileDialog :: getExistingDirectory () run with Error

VladimirPivovar

Hi
I have a problem with code: "static QString dir = QFileDialog :: getExistingDirectory ();".
When I call this code section CASE comes with an error message: "Microsoft Visual C + + Runtime Library. This application has requested the Runtime to terminate it in an unusual way". At compile time all is well. But when the - mistake. I do not know why. I tried to call in another project-the same.

I want to get the path to the selected directory.

goetz

Leave out the static in front of the QString:

@
QString dir = QFileDialog::getExistingDirectory();
@

dbzhang800

Perhaps what he want is something like this:

@
static QString dir;
if (dir.isEmpty())
dir = QFileDialog :: getExistingDirectory ();
@

VladimirPivovar

All the same run-time error:

“Microsoft Visual C + + Runtime Library. This application has requested the Runtime to terminate it in an unusual way”

lgeyer

Run your application in debug mode to find out where it actually crashes.

veeraps

Would copy the binary file (created under Release folder) to Qt bin directory and try executing it from there?

Is it crashing in debug mode as well?

VladimirPivovar

in debug and in release mode:

"QWidget: Must construct a QApplication before a QPaintDevice

Invalid parameter passed to C runtime function.
Invalid parameter passed to C runtime function.

"

I run code here:

@

#include <shlobj.h>
#include <QtGui/QApplication>
#include <QObject>
#include <QDebug>
#include <QFileInfo>

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrev,PSTR szCmdLine,int iCmdShow)
{
....
switch (uMsg)
{
case IDC_CHANGE_DIR:
static QString dir;
if (dir.isEmpty())
dir = QFileDialog :: getExistingDirectory ();
}
break;
...
}
@

VladimirPivovar

A similar problem is discussed here, but I can not figure out what to do to bring up a dialog box to select the folder:

http://www.qtforum.org/article/24470/calling-qt-gui-dll-from-mfc-application.html

dbzhang800

I couldn't figure out why you using Qt in such a way, can you give us some reasons?

[quote author="VladimirPivovar" date="1338551944"]in debug and in release mode:

"QWidget: Must construct a QApplication before a QPaintDevice

Invalid parameter passed to C runtime function.
Invalid parameter passed to C runtime function.

"

I run code here:
[/quote]

BTY, the error message is very clear, you can not construct a QWidget or it's subclass before QApplication exists.