Issue with QFileDialog

[baluk]

Hi,

I am using QFilDialog::getOpenFilename() to get the file name chosen by the user. It is working fine for me. But the issue is when the user chose to press the "Cancel" button instead of "Open". When I press the Cancel button I am closing the dialog with close signal. But program get struck after closing the window. I am confused of writing the logic between "open" and cancel" button. My code is

QString Directoryfinder::getFilename()
{
    QFileDialog *dialog;
    QString filepath = dialog->getOpenFileName(this, tr("Open File"),"/home",tr("Text files(*.txt)"));
    if(filepath.isNull())
   connect(dialog,SIGNAL(rejected()),dialog,SLOT(close()));
 
    return filepath;
}

QString Directoryfinder::getFilename()
{
    QFileDialog *dialog;
    QString filepath = dialog->getOpenFileName(this, tr("Open File"),"/home",tr("Text files(*.txt)"));
    if(filepath.isNull())
   connect(dialog,SIGNAL(rejected()),dialog,SLOT(close()));
   
    return filepath;
}

To copy to clipboard, switch view to plain text mode 

Can anyone please guide me with the logic.

Thank You,

baluk

[Lykurg]

you might want to initialize your dialog? dialog is a null pointer! and by the way your connect statement doesn't make any sense.

[franz]

QString filepath = dialog->getOpenFileName(this, tr("Open File"),"/home",tr("Text files(*.txt)"));

QString filepath = dialog->getOpenFileName(this, tr("Open File"),"/home",tr("Text files(*.txt)"));

To copy to clipboard, switch view to plain text mode 

QFileDialog::getOpenFileName() is a static function. You don't need an instance of QFileDialog for it, which is why this code is properly executed in the first place.

The following code is (arguably) better:

QString file = QFileDialog::getOpenFileName(this, tr("Open File"),"/home",tr("Text files(*.txt)"));

QString file = QFileDialog::getOpenFileName(this, tr("Open File"),"/home",tr("Text files(*.txt)"));

To copy to clipboard, switch view to plain text mode 

if(filepath.isNull())
   connect(dialog,SIGNAL(rejected()),dialog,SLOT(close()));

if(filepath.isNull())
   connect(dialog,SIGNAL(rejected()),dialog,SLOT(close()));

To copy to clipboard, switch view to plain text mode 

As lykurg said, this doesn't make sense. That is for two reasons:

• QFileDialog::getOpenFileName() is a static function and blocking function. When the function returns, the file dialog is already closed.
• dialog is uninitialized

return filepath;

return filepath;

To copy to clipboard, switch view to plain text mode 

This basically means that your function should have been:

QString Directoryfinder::getFilename()
{
    return QFileDialog::getOpenFileName(this, tr("Open File"), "/home", tr("Text files (*.txt)");
}

QString Directoryfinder::getFilename()
{
    return QFileDialog::getOpenFileName(this, tr("Open File"), "/home", tr("Text files (*.txt)");
}

To copy to clipboard, switch view to plain text mode 

When the dialog is canceled, the string will be null. When the dialog is accepted, the string will be non-null. Based on that you can make decisions. The signals and slots will be involved as soon as you stop using the static functions and start the open() paradigm.

[baluk]

oke now I have initialized the dialog. it works fine. but how can I close the dialog when the user press the "Cancel" button.

[Lykurg]

Have you tried the static version as franz had suggested? The dialog closes itself when pressing cancel.

[baluk]

Thanks to both of you for detailed explanation. It is working fine now except that I have to press "Cancel" twice before it is closed. It's not an issue but just want to know the reason.