当onAuthStateChanged（firebase）函数中的推入页面时，离子3表单验证不起作用

Question

[更新]

只需使用 authState 。它对我有用

constructor(public afAuth:AngularFireAuth,public navCtrl: NavController,) {
      this.afAuth.authState.subscribe(user => {
           if(user)
           {
                console.log('welcome')
           }
           else
           {
                this.navCtrl.push(LoginPage)
           }
      })
 }

---

我正在使用ionic3和firebase

当我导航到onAuthStateChanged（firebase）函数中的登录页面时。 我的表单在登录页面中验证无效。 仅在从站点外导航此功能时有效。

home.ts

export class HomePage {

 constructor(public afAuth:AngularFireAuth,public navCtrl: NavController,) {
      this.afAuth.auth.onAuthStateChanged(user =>{
           if(!user)
           {
                this.navCtrl.push(LoginPage
           }
      })
  }

 }

login.ts

export class LoginPage {
 loginForm: FormGroup;
 constructor(public alertCtrl: AlertController,public fb: FormBuilder,public navCtrl: NavController,public afAuth: AngularFireAuth, public navParams: NavParams) {
      this.createForm()
 }
 createForm() {
      this.loginForm = this.fb.group({
           'user': ['',Validators.compose([Validators.required]),],
           'pass': ['', Validators.compose([Validators.required])],
      });
 }
 showAlert() {
      const alert = this.alertCtrl.create({
                title: 'Something wrong',
           subTitle: 'Wrong email or password',
           buttons: ['OK']
      });
      alert.present();
 }
 login()
 {
      if(this.loginForm.valid)
      {
           var username = this.loginForm.get('user').value
           var password = this.loginForm.get('pass').value
           this.afAuth.auth.signInWithEmailAndPassword(username,password).catch((err)=>{
                console.log(err)
                this.showAlert()
           })
      }
 }

login.html

<form [formGroup]="loginForm">
      <p class="text-danger bg-dark p-2" *ngIf="loginForm.controls['user'].errors && !loginForm.controls['user'].pristine">required</p>
      <input type="text"  placeholder="Email" class="form-control input-style" formControlName="user">

      <p class="text-danger bg-dark p-2" *ngIf="loginForm.controls['pass'].errors && !loginForm.controls['pass'].pristine">required</p>
      <input type="text" placeholder="Password" formControlName="pass"  class="form-control input-style">                              
 </form>               
 <button  type="submit" [disabled]="loginForm.invalid" (click)="login()" class="ghost-round full-width">Login</button>