Question

您好，当我运行我的项目时出现上述错误吗？

import * as WebBrowser from 'expo-web-browser';
import React , {Component} from 'react';
import {PermissionsAndroid} from 'react-native';
import {
    Image,
    Platform,
    ScrollView,
    StyleSheet,
    Text,
    Button,
    TouchableOpacity,
    View,
    Switch
} from 'react-native';
import { MonoText } from '../components/StyledText';
import {Linking , SMS }from 'expo';
import * as Permissions from 'expo-permissions'

class Sendsms extends Component {
    state = {switch1Value: false}

    toggleSwitch1 = (value) => {
        this.setState({switch1Value: value});
        console.log('Switch 1 is: ' + value);

    }

    askSMSPermissionsAsync = async () => {
        await Permissions.askAsync(Permissions.SMS);
    };
    HandlePress = () =>{
        console.log('try to send sms');

    }

    render(){
        return(
            <View>
            <Text>{this.state.switch1Value ? 'Switch is ON' : 'Switch is OFF'}</Text>
            <Switch onValueChange = {this.toggleSwitch1.bind(this)} value = {this.state.switch1Value}/>
        <Button title="sendSMS"  onPress={this.askSMSPermissionsAsync} />
        </View>
    )
    }
}

我尝试重新编译项目并删除构建文件夹而没有运气我还试图将代码复制到其他项目中仍然存在错误

export default Sendsms;

Answer 1

您需要将await调用包装在try/catch中，以处理被拒绝的承诺。我不确定为什么它会被拒绝，但是您可以console.log通过以下操作找出答案：

  askSMSPermissionsAsync = async () => {
    try {
      await Permissions.askAsync(Permissions.SMS);
    } catch(e) {
      console.log(e);
    }
  };

请记住，await只是诺言的句法糖。

Answer 2

await Permissions.askAsync(Permissions.SMS);导致可能被拒绝的Promise。使用承诺时，请始终使用try {} catch(e) {}来捕获任何拒绝。检查日志以获取有关拒绝的更多信息。

所以：

askSMSPermissionsAsync = async () => {
  try {
    await Permissions.askAsync(Permissions.SMS);
  } catch (e) {
    console.error(e);
  }
};

反应本机未处理的承诺拒绝p0

2 个答案: