当stacknavigator与DrawerNavigator嵌套时，标题标题不起作用

Question

我有三个导航器，用于Auth的AuthStackNavigator，以及DrawerNavigator和AppStackNavigator。因此，AuthStackNavigator嵌套到DrawerNavigator，而DrawerNavigator嵌套到AppStackNavigator。

问题是，从DrawerNavigator导航到AppStackNavigator时，它将继续显示DrawerNavigator的标题，但应该是AppStackNavigator的标题。 （到目前为止，我已经提到header：null，因为它显示了双重header）如何解决此问题？

导航器代码：

   const AppStackNavigator = createStackNavigator({
Home: {
screen: Home,
navigationOptions: {
 header: null
}
},
StoreList: {
screen: StoreList,
navigationOptions: {
  header: null
 }
 },
});

const DrawerNavigator = createDrawerNavigator({
Dashboard: {
  screen: AppStackNavigator,
  navigationOptions: {
    drawerLabel: "Home",
  }
},
Training: {
  screen: Training,
  navigationOptions: {
    drawerLabel: "Training"
  }
},
RoutePlan: {
  screen: RouteCalendar,
  navigationOptions: {
    drawerLabel: "Route Plan"
  }
}
},
{
contentOptions: {
  activeTintColor: '#127CC1',
},
contentComponent: props => <DrawerComponent {...props}/>,
drawerOpenRoute: 'DrawerOpen',
drawerCloseRoute: 'DrawerClose',
drawerToggleRoute: 'DrawerToggle',
navigationOptions : ({navigation}) => {
  const { routeName } = navigation.state.routes[navigation.state.index];
  const headerTitle = routeName;
  return {
      headerTitle,
      headerLeft: (
        <Icon name="md-menu" style={{ marginLeft: 10 }} 
        onPress={() => navigation.toggleDrawer()}
        />
      )
    }
  }
 }
);

const AuthStackNavigator = createStackNavigator(
{
LoginScreen: {
screen: Login,
navigationOptions: {
  headerTransparent: true
}
},
 Drawer: DrawerNavigator,
});

请引导我完成这个工作！