这是我发送给Firebase的提交表单：

enter code heresubmitForm = async () => {
    const reg = /^\+?3?8?(0\d{9})$/

    if(!this.state.phone.match(reg)) {
      Alert.alert('Error', 'Wrong phone number !')
    } else if( this.state.username.length < 1) {
      Alert.alert('Error', 'Username has to be not empty !')
    } else { 
      await AsyncStorage.setItem('userPhone', this.state.phone)
      User.phone = this.state.phone
      firebase.database().ref('users/' + User.phone).set({ username: this.state.username })
      this.props.navigation.navigate('App')
    }
  }