Angular 订阅不会在 Next 上调用

Question

我正在尝试实现一个自动登录系统，将登录数据保存到本地存储，以便在刷新时从本地存储获取数据。

当我从本地存储获取数据时，我使用Subject来发出该数据，以便在 header 组件中我订阅数据并在刷新时保持应用程序状态。

现在刷新时，我的自动登录函数被调用，但订阅未在 header 组件中调用

AuthService Code

    autoLogin(){
    const userdata: {
        email:string;
        id: string;
        _token:string;
        _tokenExpairDate:Date;
    }=JSON.parse(localStorage.getItem('userData'));

    if(!userdata){
      return;
    }

    console.log("Auto Login Call");
    
    const loadedData=new User
    (
      userdata.email,
      userdata.id,
      userdata._token,
      new Date
      (
        userdata._tokenExpairDate
      )
    );

    if(loadedData.token){
      console.log(loadedData);
      console.log("data Emmit");
      this.user.next(loadedData);
    }
    else{
      console.log("data Not Emmit");
    }
 }

header component code

ngOnInit(){
    this.userSub=this.auth.user.subscribe(user=>{
      console.log("Subscription Call");
      this.isLogin=!user? false:true;
    })
  }

Answer 1

我不确定你实际上是如何设置可观察的，但这可能对你有帮助。

// In user.modal.ts export a interface for the user
// You need to define this so that you dont need to repeat your code

export interface User {
    email:string;
    id: string;
    _token:string;
    _tokenExpairDate:Date;
}
************************************
// In your service file, do this: 

import { User } from './user.modal.ts';

let initialUserDetails: User = {};

private userDetailsSource: BehaviorSubject<User> = new BehaviorSubject<User>(this.initialUserDetails);

public userDetailsObservable: Observable<User> = this.userDetailsSource.asObservable();

setUserDetails(userDetails: User) {
    this.userDetailsSource.next(userDetails);
}

getUserDetails(): Observable<User> {
    return this.userDetailsObservable;
}

********************************
// In your component.ts file, whenever you want to set the details: 

if (loadedData.token) {
    console.log(loadedData);
    console.log("data Emmit");
    this.user.next(loadedData); // Dont do this:

    this.yourServiceName.setUserDetails(loadedData); // Do this;
}


// Whenever you want to get the details of the Observable, you can do this: 

this.yourServiceName.getUserDetails().subscribe(subscribedData => {
    console.log('Latest Observable Data =>', subscribedData);
})