angular - InvalidPipeArgument : '[object Object]' for pipe 'AsyncPipe'

在服务中这样声明:

public currentDBUserBS$: any;

constructor(private afDb: AngularFireDatabase){}

fetchUser(uid){
  this.afDb.object(`users/${uid}`).valueChanges().subscribe((dUser) => {
    if (dUser) {
      this.currentDBUserBS$ = dUser;
    }
  });
}

现在尝试在模板中使用

template: `<li *ngIf="(authService.currentDBUserBS$ | async)?.role=='admin'"> Something </li>`

错误堆栈:

ERROR Error: InvalidPipeArgument: '[object Object]' for pipe 'AsyncPipe'
    at invalidPipeArgumentError (common.js:4219)
    at AsyncPipe._selectStrategy (common.js:5630)
    at AsyncPipe._subscribe (common.js:5612)
    at AsyncPipe.transform (common.js:5586)
    at Object.View_AppNavigatorComponent_0._co [as updateDirectives] (AppNavigatorComponent.html:40)
    at Object.debugUpdateDirectives [as updateDirectives] (core.js:14339)
    at checkAndUpdateView (core.js:13508)
    at callViewAction (core.js:13858)
    at execComponentViewsAction (core.js:13790)
    at checkAndUpdateView (core.js:13514)

最佳答案

您正在给currentDBUserBS$从Firebase而不是Observable中获取的对象。如果要这样做，则必须删除模板中的| async。

但是，您可以执行以下操作:

fetchUser(uid){
  this.currentDBUserBS$ = this.afDb.object(`users/${uid}`).valueChanges();
}

.valueChanges()使您可以观察到，并会在发出新值或修改现有值时自动更新。

关于angular - InvalidPipeArgument : '[object Object]' for pipe 'AsyncPipe' ，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47529286/