[pyqt5]如何改变QListView选择项

self.listView = QtWidgets.QListView(self.centralwidget)
self.listView.setGeometry(QtCore.QRect(0, 30, 241, 631))
self.listView.setObjectName("listView")

string_model = QStringListModel()  # 创建model
string_model.setStringList(['1','2','3'])  # 将数据设置到model
self.listView.setModel(string_model)

model_index=string_model.index(i,0)
self.listView.setCurrentIndex(model_index)
string_model.setData(model_index, (255,0,0), Qt.BackgroundColorRole)