style not working with QItemDelegate

Question

I have a QTreeview and I used this stylesheet

QTreeView#treeView::item:selected:active
{
    background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0 #6ea1f1, stop: 1 #567dbc);
}
QTreeView#treeView::item:hover
{
    background: qlineargradient(x1:0, y1:0, x2:0, y2:1, stop:0 #e7effd, stop:1 #cbdaf1);
    border: 1px solid #bfcde4;
}
QTreeView#treeView::item:has-children
{
    background: qlineargradient(x1:0, y1:0, x2:0, y2:1, stop:0 #cccccc, stop:1 #aaaaaa);
    border: 1px solid #777777;
    border-left: 0;
    border-right: 0;
    font-weight: bold;
}

It works fine. But wen I use

self.treeView.setItemDelegate(GenericDelegate())

Where GenericDelegate is defined as bellow

class GenericDelegate(QItemDelegate):

    def _init_(self, parent=None):
        super(GenericDelegate, self)._init_(parent)

    def createEditor(self, parent, option, index): 
        if index.row()==1:
            cb = QtGui.QComboBox(parent)
            cb.addItems('A')
            cb.addItems('B')
            return cb

My style doesn't work any more!
I am doing something wrong?

Answer 1

I should use

QStyledItemDelegate

instead of

QItemDelegate 

It works now!