[英]Cannot read property 'authorize' of undefined react-native-app-auth
[英]React Native : Cannot read property 'isConnected' of undefined (detect app connection)
我需要在我的應用中檢查用戶與互聯網的連接。 我嘗試使用NetInfo,但出現此錯誤:
無法讀取未定義的屬性“ isConnected”
我還在AndroidManifest.xml
文件中添加了權限,但這沒有幫助。
這是我的代碼:
NetInfo.isConnected.fetch().then(isConnected => {
if (isConnected) {
this.setState({
loading: true,
})
var url = 'https://api.apixu.com/v1/current'+this.state.cityname
return fetch(url)
.then((data) => data.json())
.then((datajson) => {
this.setState({
loading: false,
fetched: true,
})
console.log(this.state.localtime)
})
.catch((error) => { console.error(error) })
} else {
Alert.alert("You are offline!");
}
是什么導致此問題?
import {NetInfo} from 'react-native';
constructor(props) {
super(props);
this.state = {
isNetConnected: true,
}
}
async componentDidMount() {
NetInfo.isConnected.addEventListener(
'connectionChange',
this._handleConnectivityChange
);
NetInfo.isConnected.fetch().done((isConnected) => {
if(isConnected == true)
{
this.setState({isNetConnected: true})
}
else
{
this.setState({isNetConnected: false})
}
});
}
_handleConnectivityChange = (isConnected) => {
if(isConnected == true)
{
this.setState({isNetConnected: true})
this.getActivitiesAndNotifications()
}
else
{
this.setState({isNetConnected: false})
}
};
像這樣使用。 現在,如果沒有任何互聯網連接,“ isNetConnected”將觸發
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