Hi there, I have a QListView that displays pdf files from a Directory. To achieve this, I linked the QListView to the QFileSystemModel. My problem is that I need to be able to search for a file in the QListView using a pattern string, so I employed the use of a QSortFilterProxyModel. The QSortFilterProxyModel works fine except that it doesn't filter when I search for a particular file. Please see my code below.
Qt Code: 
  1. MainWindow::MainWindow(QWidget *parent) :
  2.     QMainWindow(parent),
  3.     ui(new Ui::MainWindow)
  4. {
  5.     ui->setupUi(this);
  6.  
  7.     ui->listView_Main->setFlow(QListView::TopToBottom);
  8.     ui->listView_Main->setViewMode(QListView::ListMode);
  9.     ui->listView_Main->setWrapping(true);
  10.     ui->listView_Main->setResizeMode(QListView::Adjust);
  11.     ui->listView_Main->setUniformItemSizes(true);
  12.  
  13.     QString root_path = "C:/Users/C5248134/Desktop/Projects/build-Ithala-Desktop_Qt_5_7_0_MSVC2015_64bit-Debug/Documents/";
  14.  
  15.     proxyModel = new QSortFilterProxyModel(this);
  16.  
  17.     f_model = new QFileSystemModel(this);
  18.     f_model->setFilter(QDir::Files);
  19.  
  20.     proxyModel->setSourceModel(f_model);
  21.     proxyModel->setFilterRole(Qt::DisplayRole | Qt::DecorationRole);
  22.  
  23.     if(f_model->rootDirectory().exists())
  24.         qDebug() << "Dir Found" <<endl;
  25.     else
  26.         qDebug() << "Dir not found" <<endl;
  27.  
  28.     ui->listView_Main->setModel(proxyModel);
  29.     ui->listView_Main->setRootIndex(proxyModel->mapFromSource(f_model->setRootPath(root_path)));
  30. }
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Search button clicked slot.
Qt Code: 
  1. void MainWindow::on_btnSearch_clicked()
  2. {
  3.     QString patternStr = ui->leSearch->text();
  4.     QFileInfoList fileInfoObj = f_model->rootDirectory().entryInfoList();
  5.  
  6.     proxyModel->setFilterFixedString(patternStr);
  7.     //ui->listView_Main->setRootIndex();
  8. }
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When I type-in a search string and then click on the search button the entire QListView goes blank. Please see screenshots of how my app looks before and after I search for a file.
Beforescreen2.jpg AfterBlankPic.jpg