1

我的 Firebase 数据库中有一些数据，这些数据我想通过FormBuilder. 它工作得有些好，但我经常出错而不是说formGroup expects a FormGroup instance. Please pass one in.。

没有意义的是，当我对数据库应用导致订阅触发的新更改时，我收到错误消息。尽管this.settingsForm在更新后订阅运行之前和之后设置。

这是订阅：

this.eventSubscription = this.af.database.object('/events/' + this.eventId).subscribe(
  (event: IEvent) => {

    const rsvp: IRSVP = event.rsvp;
    const settings: ISettings = event.settings;
    const tickets: ITickets = event.tickets;

    this.settingsForm = this.fb.group({
      collaborators: this.fb.array(settings.collaborators || []),
      isRSVPOpen: settings.isRSVPOpen,
      isAutoApproveToGuestlist: settings.isAutoApproveToGuestlist,
      rsvp: this.fb.group({
        latestDate: [rsvp.latestDate, [Validators.required]],
        latestTime: [rsvp.latestTime, [Validators.required]],
        guestLimit: [rsvp.guestLimit, [Validators.required]],
        isGuestPlusOne: rsvp.isGuestPlusOne,
        isAutoApproveToGuestlist: rsvp.isAutoApproveToGuestlist,
        isOnlyFacebookRSVP: rsvp.isOnlyFacebookRSVP,
        isBirthdayAndPhoneRequired: rsvp.isBirthdayAndPhoneRequired
      }),
      tickets: this.fb.group({
        info: this.fb.group({
          closingDate: tickets.info.closingDate,
          closingTime: tickets.info.closingTime
        }),
        types: this.fb.array(tickets.types || [])
      })
    });
  }
);

所以我想知道为什么会发生这种情况，我该如何预防呢？我不能像这样初始化表格吗？

4

1 回答 1

1

使用*ngIf="settingsForm".

如果您有一个尚未初始化的 FormGroup，则不能在模板中使用它。例如，如果settingsForm尚未初始化，则以下内容将不起作用：

<form [formGroup]="settingsForm ">
  <input formControlName="name" />
</form>

改为这样做：

<form *ngIf="settingsForm" [formGroup]="settingsForm ">
  <input formControlName="name" />
</form>
于 2017-03-08T23:18:45.660 回答