Qt6.2.2 MessageDialog and FileDialog QML Type issue

fromis_9

Hi. I'm using Qt 6.2 and I want to use FileDialog and MessageDialog from QtQuick.Dialogs.
But this docs says the MessageDialog is not included in QtQuick.Dialogs of Qt 6.2.
Although I tried to use the MessageDialog in QML, the compiler said that I needed to include Qt Widgets module to my project. So I did it, and it worked. So now I can use 'FileDialog' and 'MessageDialog' both in my project using Qt 6.2.
However, after I included the 'Qt Widgets' module in my project, I couldn't use the FileDialog's currentFile property, with following error: "ReferenceError: selectedFile is not defined" I had used it before including Qt Widgets. Anyone know why?

Target platform: Windows 10
Using IDE: Visual Studio 2019 with Qt extension
Using Qt versions: 6.2.2_msvc2019_62
Using Modules: core, gui, widgets, qml, quickwidgets, quick, quickcontrols2

code

/// main.cpp

#include <QApplication>
// ...
int main(int argc, char** argv)
{
  QApplication app(argc, argv); 
  // .. some codes..
  return app.exec();
}

/// qml
import QtQuick 2.9
import QtQuick.Controls 2.12
import QtQuick.Window 2.15
import QtQuick.Dialogs
import Qt.labs.platform

Window {
  // some codes
  MessageDialog {
    // some codes
  }
  FileDialog {
    fileMode: FileDialog.SaveFile // works
    defaultSuffix: "avi" // works
    nameFilters: [ "avi (*.avi)" ] // works
    function saveopen() {
      currentFIle = new Date().toLocaleString(Qt.locale(), "yyMMddHHmmss")
      open() // works
    }
    onAccepted: {
      let fullLen = selectedFile.length // not defined 'selectedFile'
      var name = selectedFile.toString().substring(8, fullLen - 4)
      mycppbackend.method(name)
    }
  }
}

fromis_9

I need to use Qt.labs.platform, rather QtQuick.Dialogs module because former contains MessageDialog and FileDialog both but latter is not. So I removeed "import QtQuick.Dialogs" above code. However, FileDialog from Qt.labs.platform does not contain "selectedFile" property, so I switch it to "currentFile" and it works.