相关疑难解决方法(0)

我不知道为什么我的React组件渲染两次.所以我从params中提取一个电话号码并将其保存到状态,以便我可以搜索Firestore.一切似乎工作得很好,除了它呈现两次......第一个呈现电话号码和零点.第二次渲染所有数据都正确显示.有人可以指导我解决方案.

class Update extends Component {
constructor(props) {
    super(props);
    const { match } = this.props;
    this.state = {
        phoneNumber: match.params.phoneNumber,
        points: 0,
        error: ''
    }
}

getPoints = () => {
    firebase.auth().onAuthStateChanged((user) => {
        if(user) {
            const docRef = database.collection('users').doc(user.uid).collection('customers').doc(this.state.phoneNumber);
            docRef.get().then((doc) => {
                if (doc.exists) {
                const points = doc.data().points;
                this.setState(() => ({ points }));
                console.log(points);
                } else {
                // doc.data() will be undefined in this case
                console.log("No such document!");
                const error = 'This phone number is not registered yet...' …