如何将多个值传递给AsyncValidator reactForm

Question

这是我的asyncValidator代码，工作正常。

myForm = this.fb.group({
    userName: ['', {
      validators: [Validators.required,
      asyncValidators: [this.isExistsValidator.bind(this)],
      updateOn: 'blur'
    }],
    email: ['', [Validators.required]]
  });

验证器

  isExistsValidator(control: AbstractControl): { [key: string]: any } {
    return new Promise(resolve => {
        this.haser.isExists(control.value).subscribe(
          d => { (d.r) ? resolve({ "duplicate": true }) : resolve(null); })
    })
  }

我也想将email.value传递给此验证器。