firebase.auth().onAuthStateChanged((user) => {
if(user) {
this.isLoggedIn = true; //Set user loggedIn is true;
this.isAdmin = false;
firebase.database().ref('/userProfile/' + user.uid).once('value').then(function(snapshot) {
let userInfo = snapshot.val();
if(userInfo.isAdmin == true) {
//ERROR AT THIS LINE:
//Error: Uncaught (in promise): TypeError: Cannot set property 'isAdmin' of null
this.isAdmin = true;
console.log(userInfo);
}
});
} else {
this.isLoggedIn = false; //Set user loggedIn is false;
}
});
我在第8行遇到错误
Error: Uncaught (in promise): TypeError: Cannot set property ‘isAdmin’ of null
请帮忙！
要么你可以使用箭头功能
原文链接：https://www.f2er.com/angularjs/240387.htmlfirebase.database().ref('/userProfile/' + user.uid).once('value')
.then((snapshot) => {
或使用
var self = this;
firebase.database().ref('/userProfile/' + user.uid).once('value')
.then(function(snapshot) {
self.isAdmin = true;
另见https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Functions/Arrow_functions
