无法在 React Native 中动态设置 header 标题

Question

我正在尝试动态更改新组件屏幕的 Header 标题，但出现以下错误：

TypeError: TypeError: undefined is not an object (evaluating 'navigationData.navigation.getParam')
* screens\CategoryMealsScreen.js:26:42 in navigationOptions
* screens\CategoryMealsScreen.js:10:40 in CategoryMealsScreen
- node_modules\react-native\Libraries\Renderer\oss\ReactNativeRenderer-dev.js:9473:27 in renderWithHooks
- node_modules\react-native\Libraries\Renderer\oss\ReactNativeRenderer-dev.js:11994:6 in mountIndeterminateComponent

我的代码：

import React from "react";
import { Text, View, StyleSheet, Button } from "react-native";
import { CATEGORIES } from "../data/dummydata";
import Colors from "../constans/Colors";
let titleHeader = "";
const CategoryMealsScreen = props => {
  const categoryId = props.navigation.getParam("categoryId");

  const selectedCategory = CATEGORIES.find(cat => cat.id === categoryId);
  CategoryMealsScreen.navigationOptions(selectedCategory.title);
  // console.log(Object.keys(props.navigation));
  titleHeader = selectedCategory.title;
  return (
    <View style={styles.screen}>
      <Text>{selectedCategory.title}</Text>

      <Button
        title="Meals Details"
        onPress={() => props.navigation.navigate("MealsDetail")}
      />
    </View>
  );
};

CategoryMealsScreen.navigationOptions = navigationData => {
  const catId = navigationData.navigation.getParam("categoryId");
  const selectedCategory = CATEGORIES.find(cat => cat.id === catId);
  // console.log(catId);
  // console.log(navigationData.navigation.getParam("categoryId"));
  return {
    headerTitle: selectedCategory.title,
    headerStyle: {
      backgroundColor: Colors.primaryColor
    },
    headerTintColor: "white"
  };
};

const styles = StyleSheet.create({
  screen: {
    flex: 1,
    justifyContent: "center",
    alignContent: "center"
  }
});

export default CategoryMealsScreen;

我尝试控制台日志 catId，它确实在控制台中显示了输出，但错误仍然存在。

我可以在组件内部使用 getParam 获取数据，但不能在 CategoryMealsScreen.navigationOptions

中获取数据

有些人发现它的问题与 bable 配置有关，但它不工作或者我做错了什么。不对，我正在使用全局变量 titleHeader 来更改 header 标题并且它有效，但它仍然是一个 hack。

GitHub

Answer 1

问题发生是因为 async task like find CATEGORIES.find(cat.. This will take a time to complete

解决方案 : 使用 async/await 你的功能等待你的任务完成。

We can set title dynamically using navigationOptions directly in stack configuration.  

CategoryMeals : {
    screen : CategoryMealsScreen,
    navigationOptions: ({ navigation }) => ({
          title : navigation.getParam('categoryId', 'CategoryMeals')
    }),
},

无法在 React Native 中动态设置 header 标题

Unable to set header title dynamically in react native

react-native

react-navigation

react-navigation-stack