Question

我尝试在登录成功时重定向我的用户，但我收到了此错误：＆＃34;未定义不是对象（评估＆＃39; _this2.props.navigation＆＃39;）＆＃34 ;

这是我在App.js中的代码：

const Homepage = StackNavigator({
 Home: {screen: Home},
 Store: {screen: Store},
 Admin: {screen: Admin},
});

这是我在Store.js中的代码，我在登录时尝试重定向用户：

<Button style={{color:'gray', borderColor: 'gray'}} onPress={() => 
this.login()} title="Me connecter" />

login(){
    firebase.auth().signInWithEmailAndPassword(this.state.emailLogin, 
    this.state.passwordLogin).then(function(user) {
        // Send the user to the next step
        setTimeout(() => {
            const { navigate } = this.props.navigation; 
            navigate('Admin');
        }, 1500);
    }).catch(function(error) {
        console.log('error');
        var errorCode = error.code;
        var errorMessage = error.message;

        if (errorCode === 'auth/wrong-password') {
            alert('Wrong password.');
        } else {
            alert(errorMessage);         
        }
        console.log(error);
    });
}

提前感谢您的时间和宝贵的答案。

Answer 1

为了能够使用this，你需要绑定函数，

更改此代码，

firebase.auth().signInWithEmailAndPassword(this.state.emailLogin, 
    this.state.passwordLogin).then(function(user) { /* rest of your code */ })

到此，

firebase.auth().signInWithEmailAndPassword(this.state.emailLogin, 
    this.state.passwordLogin).then((user) => { /* rest of your code */ })

或者，

firebase.auth().signInWithEmailAndPassword(this.state.emailLogin, 
    this.state.passwordLogin).then(function(user) { /* rest of your code */ }.bind(this))

React Native，Navigation：＆＃34; Undefined不是一个对象＆＃34;

1 个答案: