在createSwitchNavigator中反应本机createStackNavigator

Question

我正在尝试实现这种结构：

- Landing page
  - Login button
  - Search button

当我单击登录时，它会带我到页面没问题：

但是，如果我单击搜索按钮，它将显示以下内容：

只有在createStackView中有一个标题时，登录页面的外观才如此。

点击搜索按钮的内容应该是包含搜索目标文本的页面。

这是我的代码：

import React, { Component } from "react";
import { StyleSheet, Text, View } from "react-native";
import { createStackNavigator, createSwitchNavigator } from "react-navigation";

import Landing from "./src/components/Landing";
import Login from "./src/components/Login";

import SearchLanding from "./src/components/Landing";
import SearchByText from "./src/components/SearchByText";
import SearchByScan from "./src/components/SearchByScan";

const AppStack = createSwitchNavigator({
 Landing: { screen: Landing },
 Login: { screen: Login },
 Search: {
  screen: createStackNavigator({
    SearchLanding: { screen: SearchLanding },
    SearchByText: { screen: SearchByText },
    SearchByScan: { screen: SearchByScan }
  })
}
});

class App extends Component {
 render() {
   return <AppStack />;
 }
}

export default App;