同一屏幕在反应导航中的stacknavigation中呈现两次或三次

Question

相同的屏幕渲染两次，如屏幕截图所示。怎么能解决这个问题？

同一屏幕多次

＆＃34; react-navigation＆＃34;：＆＃34; ^ 1.0.0-beta.11＆＃34;，

import Login from "../components/login/";
import Signup from "../components/signup/";

HomeDrawerRouter.navigationOptions =（{navigation}）=＆gt; （{   header：null }）;

const screens = {
  Login: { screen: Login, path: 'Login/:messageScreen', navigationOptions: {
        gesturesEnabled: false, header: null
    }   },
  Signup: { screen: Signup, navigationOptions: {
        gesturesEnabled: false, header: null
    } }}

let MainStackRouter = StackNavigator(screens,
{
  initialRouteName: index
})

const navigateOnce = getStateForAction => (action, state) => {
  const { type, routeName } = action
  return state &&
    type === NavigationActions.NAVIGATE &&
    routeName === state.routes[state.routes.length - 1].routeName
    ? null
    : getStateForAction(action, state)
}
MainStackRouter.router.getStateForAction = navigateOnce(
  MainStackRouter.router.getStateForAction
)