QProgressDialog locks process until dismissed

[pally_sandher]

I'm trying to implement a QProgressDialog as a "busy" prompt to give the user some feedback that something is happening while a function executes but my code shows the QProgressDialog & doesn't continue processing the rest of the code unless I close the QProgressDialog using the close button.

QWinWidget win( launchParams.hWndParent );
 
      QProgressDialog progress ("Initializing Model Viewer II\nPlease wait...", QString(), 0, 0);
      progress.setWindowModality(Qt::WindowModal);
      progress.exec();
 
      gModelViewer = new VE2Modelviewer ( launchParams.flags, QString::fromAscii(launchParams.veXMLPath), &win );
      if( gModelViewer->LoadModel( launchParams.veXMLPath ) )
      {
        gModelViewer->show();
        progress.hide();

QWinWidget win( launchParams.hWndParent );

      QProgressDialog progress ("Initializing Model Viewer II\nPlease wait...", QString(), 0, 0);
      progress.setWindowModality(Qt::WindowModal);
      progress.exec();

      gModelViewer = new VE2Modelviewer ( launchParams.flags, QString::fromAscii(launchParams.veXMLPath), &win );
      if( gModelViewer->LoadModel( launchParams.veXMLPath ) )
      {
        gModelViewer->show();
        progress.hide();

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this just sits with the progressbar in the QProgressDialog looping endlessly. gModelViewer will never be shown without user interaction dismissing the QProgressDialog.

Any help would be most appreciated.

[pally_sandher]

Changing the code to the following makes it work as intended but the progress bar doesn't animate.

QProgressDialog progress("Initializing Model Viewer II\nPlease wait...", QString(), 0, 0);
    progress.show();
    qApp->processEvents();
    try
    {
      QWinWidget win( launchParams.hWndParent );
      gModelViewer = new VE2Modelviewer ( launchParams.flags, QString::fromAscii(launchParams.veXMLPath), &win );
      if( gModelViewer->LoadModel( launchParams.veXMLPath ) )
      {
        gModelViewer->show();
        progress.hide();

QProgressDialog progress("Initializing Model Viewer II\nPlease wait...", QString(), 0, 0);
    progress.show();
    qApp->processEvents();
    try
    {
      QWinWidget win( launchParams.hWndParent );
      gModelViewer = new VE2Modelviewer ( launchParams.flags, QString::fromAscii(launchParams.veXMLPath), &win );
      if( gModelViewer->LoadModel( launchParams.veXMLPath ) )
      {
        gModelViewer->show();
        progress.hide();

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Getting the progress bar to animate would be the only remaining step.

Again any help is most appreciated.

[high_flyer]

Why should it animate? you gave it min and max both 0 any you are not setting any new values as the progress goes on.

[pally_sandher]

Why should it animate? you gave it min and max both 0 any you are not setting any new values as the progress goes on.

http://qt-project.org/doc/qt-4.8/qpr...r.html#details

If minimum and maximum both are set to 0, the bar shows a busy indicator instead of a percentage of steps. This is useful, for example, when using QFtp or QNetworkAccessManager to download items when they are unable to determine the size of the item being downloaded.

[high_flyer]

I see.
I thought your wanted to animate the progress as it goes on...

I just tried it on a test project and it works perfectly. Windows 7, MSVC8, Qt8.

[pally_sandher]

I suspect us mixing MFC & Qt is where the problem lies then.

[Lesiok]

Please read this article

[Surendil]

As I remember, you may also set -1 to progress bar