Cannot read property 'navigate' of undefined in react-navigation

问题

I have used import { StackNavigator } from 'react-navigation'; in my Router.js

import { StackNavigator } from 'react-navigation';
import LoginForm from './components/LoginForm';
import EmployeeList from './components/EmployeeList';
import EmployeeCreate from './components/EmployeeCreate';

const RouterComponent = StackNavigator(
{
  LoginForm: {
    screen: LoginForm,
    navigationOptions: {
      title: 'Please Login'
    }
  },
  EmployeeList: {
    screen: EmployeeList,
  },
  EmployeeCreate: {
    screen: EmployeeCreate,
    navigationOptions: {
      title: 'Create Employee'
    }
  }
},
{
  initialRouteName: 'LoginForm',
}
);

export default RouterComponent;

Of course i use it in my App.js

import React from 'react';
import { Provider } from 'react-redux';
import { createStore, applyMiddleware } from 'redux';
import ReduxThunk from 'redux-thunk';
import reducers from './src/reducers';
import Router from './src/Router';

export default class App extends React.Component {
  render() {
    const store = createStore(reducers, {}, applyMiddleware(ReduxThunk));

    return (
      <Provider store={store}>
        <Router />
      </Provider>
    );
  }
}

And i can use this.props.navigation in my LoginForm.js like this function:

  onButtonPress() {
    const { email, password, navigation } = this.props;

    this.props.loginUser({ email, password, navigation });
  }

I pass navigation to my Action file , i can use it to navigate another screen , like this:

const loginUserSuccess = (dispatch, user, navigation) => {
  dispatch({
    type: LOGIN_USER_SUCCESS,
    payload: user
  });
  //navigation is from LoginForm.js , navigate to EmployeeList is working
  navigation.navigate('EmployeeList');
};

Now i try to use this.props.navigation.navigate in my ListItem.js

My ListItem is under EmployeeList.js

Here is my EmployeeList.js

import _ from 'lodash';
import React, { Component } from 'react';
import { connect } from 'react-redux';
import { View, Text, Button, FlatList } from 'react-native';
import { employeesFetch } from '../actions';
import ListItem from './ListItem';

class EmployeeList extends Component {
  static navigationOptions = ({ navigation }) => ({
    title: 'EmployeeList',
    headerLeft: null,
    headerRight: <Button title="Add" onPress={() => navigation.navigate('EmployeeCreate')} />,
  });

  componentWillMount() {
    this.props.employeesFetch(); 
  }
  // Using ListItem over here
  renderRow(employee) {
    return <ListItem employee={employee} />;
  }

  render() {
    console.log(this.props);
    return (
      <FlatList
        data={this.props.employees}
        renderItem={this.renderRow}
        keyExtractor={employee => employee.uid}
      />
    );
  }
}

const mapStateToProps = state => {
  const employees = _.map(state.employees, (val, uid) => {
    return { ...val, uid };
  });

  return { employees };
};

export default connect(mapStateToProps, { employeesFetch })(EmployeeList);

Here is my problem use this.props.navigation.navigate in ListItem.js

import React, { Component } from 'react';
import { Text, View, TouchableWithoutFeedback } from 'react-native';
import { CardSection } from './common';

class ListItem extends Component {

  onRowPress() {
    this.props.navigation.navigate('EmployeeCreate');
  }

  render() {
    const { item } = this.props.employee;
    return (
      <TouchableWithoutFeedback onPress={this.onRowPress.bind(this)}>
        <View>
          <CardSection>
            <Text style={styles.titleSytle}>
              {item.name}
            </Text>
          </CardSection>
        </View>
      </TouchableWithoutFeedback>
    );
  }
}

const styles = {
  titleSytle: {
    fontSize: 18,
    paddingLeft: 15
  }
};

export default ListItem;

I can use this.props.navigation in my LoginForm.js , i can't figure it out why i use it in ListItem.js navigate is undefined ?

Any help would be appreciated. Thanks in advance.

回答1:

in file EmployeeList.js pass navigation as prop to ListItem.

renderRow(employee) {
  return <ListItem employee={employee} navigation={this.props.navigation} />;
}

Now you should be able to access navigation using this.props.navigation inside ListItem.js.

Just an observation, never bind methods to context inside the render function as it is called repeatedly and a new instance will be created each time. Change your ListItem.js as below.

class ListItem extends Component {

  constructor(props) {
    super(props);
    this.onRowPress = this.onRowPress.bind(this);  // here we bind it
  }

  onRowPress() {
    this.props.navigation && this.props.navigation.navigate('EmployeeCreate');
  }

  render() {
    const { item } = this.props.employee;
    return (
      <TouchableWithoutFeedback onPress={this.onRowPress}>
        <View>
          <CardSection>
            <Text style={styles.titleSytle}>
              {item.name}
            </Text>
          </CardSection>
        </View>
      </TouchableWithoutFeedback>
    );
  }
}

回答2:

Use withNavigation. In your ListItem.js file add import { withNavigation } from ‘react-navigation’; and replace export default ListItem; with export default withNavigation(ListItem);

来源：https://stackoverflow.com/questions/49838595/cannot-read-property-navigate-of-undefined-in-react-navigation