来自导航的 React Native 调用函数

Question

我正在使用 React 原生导航。（堆栈导航）。但是我不能在 navigationOptions 中调用函数。不工作。

import React, { Component } from 'react';
import { StyleSheet, View, Text, TouchableHighlight, AsyncStorage, Alert } from 'react-native';
import { Button } from 'react-native-elements';
import Icon from 'react-native-vector-icons/FontAwesome';
import HandleBack from '../../HandleBack';

export default class Dashboard extends Component {
    constructor(props) {
        super(props);
    }

    static navigationOptions = ({ navigation }) => {
        return {
            title: 'Dasboard',
            headerLeft: null,
            headerRight: (
                <TouchableHighlight underlayColor='transparent' onPress={this.login.bind(this)} style={{marginRight: 10}}>
                    <Icon
                        name="power-off"
                        size={25}
                        color="white"
                    />
                </TouchableHighlight>
            )
        };
    };

    login() {
        alert('Button clicked!');
    }

    onBack = () => {
        this.props.navigation.navigate('Screen3');
    };    

    render() {        
        return(
            <HandleBack onBack={ this.onBack }>
                <View>
                    <Text> This is screen 2 </Text>
                    <TouchableHighlight onPress={() => this.props.navigation.navigate('Screen3')}> 
                        <Text> Go to Screen 3 </Text>
                    </TouchableHighlight>
                </View>
            </HandleBack>
        )
    }
}

当我使用onPress={this.login.bind(this)}获取错误

“类型错误：类型错误：未定义不是对象（评估'_class.login.bind'）”

当我使用 onPress={this.login}没有反应。

当我使用onPress={this.login()}获取错误

TypeError: TypeError: _class.login 不是函数。

但

我正在使用onPress={() => alert('test')}。

Answer 1

您可以使用 setParams 或 getParams 进行反应导航来实现它。

export default class Dashboard extends Component {


    static navigationOptions = ({ navigation }) => {
        return {
            title: 'Dasboard',
            headerLeft: null,
            headerRight: (
                <TouchableHighlight underlayColor='transparent' 
                 onPress={navigation.getParam('login')} //call that function in onPress using getParam which we already set in componentDidMount
                   style={{marginRight: 10}}>
                    <Icon
                        name="power-off"
                        size={25}
                        color="white"
                    />
                </TouchableHighlight>
            )
        };
    };
   login() {
        alert('login click')
    }
    onBack = () => {
        this.props.navigation.navigate('Screen3');
    };    

componentDidMount() {
        this.props.navigation.setParams({ login: this.login }); //initialize your function
    }
    render() {        
        return(
          .....
        )
    }
}