“未定义不是函数”错误。为什么不工作？

Question

 import React from "react"; import {StackNavigator} from "react-navigation"; import StartScreen from "../screens/start";


 export default StackNavigator( {   Start: {
     screen: StartScreen   } }, {   initialRouteName:"Start",   navigationOptions:{
     headerSryle:{
       backgroundColor:"#f4511e"
     },
     headerTitleStyle:{
       textAlign:"center",
       alignSelf:"center",
       fontSize:20,
       color:"#fff",
       fontWeight:"bold"
     }   }  } )

Answer 1

您应该编写类似的内容：

const HomeStack = StackNavigator({ ...

然后

export default HomeStack;