I used tree to show my data in tree view in my tabs, which existed in main window. I think I may need a parser to pares my data, which are on the newly created file, also using setupModelData method in treeModel.cpp, and add it to my tree model.

I am still worḱing on it.

If you created a file I suppose you have a "QFile":http://qt-project.org/doc/qt-4.8/qfile.html or any other reference to access it? If you do, you can access the file content with a "QDataStream":http://qt-project.org/doc/qt-4.8/qdatastream.html or "QTextStream":http://qt-project.org/doc/qt-4.8/qtextstream.html and display it? What do you want to do with a tree view?

Please provide some more description about what you want to do and the layout of your code. Maybe you could provide some snippets too?