Wt

Here is my code:

    view = new WTableView;
    gridLayout = new WGridLayout;
    int rows = 5;
    int columns = 4;
    model = new WStandardItemModel(rows, columns, this);
    gridLayout->addWidget(view, 0,0);
    root()->setLayout(gridLayout);
    for (int row = 0; row < rows; ++row) {
       for (int column = 0; column < columns; ++column) {
         Wt::WStandardItem *item = new Wt::WStandardItem();
         item->setText("Item " + boost::lexical_cast<std::string>(row)
                       + ", " + boost::lexical_cast<std::string>(column));
         model->setItem(row, column, item);
       }
     }
    model->setHeaderData(0, Horizontal, std::string("Header 1"));
    model->setHeaderData(1, Horizontal, std::string("Header 2"));
    model->setHeaderData(2, Horizontal, std::string("Header 3"));
    model->setHeaderData(3, Horizontal, std::string("Header 4"));
    cout <<  boost::any_cast<std::string>(model->headerData(3, Horizontal)) << endl; // ouput: Header 4 (works)
    view->setAlternatingRowColors(true);
    view->setModel(model);

but no header row is visible and no formatting available (like alternating row colors).

What am I doing wrong?