离子iOS构建故障，错误显示为按钮错误

Question

  

我有一个组件，可以从多个组件中调用。组件下方

<ion-content>
<form [formGroup]="registerForm" (submit)="onSubmit(registerForm.value)">

    <ion-row>
        <ion-col class="input-column" col="12">
            <ion-item>
                <ion-input type="password" maxlength="4" placeholder="PIN" formControlName="password" pattern="^[0-9]*$"></ion-input>
            </ion-item>
            <ion-icon name="medical"></ion-icon>
        </ion-col>
    </ion-row>
    <span *ngIf="registerForm.controls.password.hasError('required') && registerForm.controls.password.touched"
        class="error">*PIN is required.</span>
    <span *ngIf="registerForm.controls.password.hasError('minlength') && !registerForm.controls.password.hasError('required') && registerForm.controls.password.touched"
        class="error">*PIN length must be 4.</span>
    <span *ngIf="!registerForm.controls.password.hasError('minlength') && registerForm.controls.password.hasError('pattern') && registerForm.controls.password.touched"
        class="error">*PIN must be a number.</span>


    <button ion-button full color="primary" [disabled]="!registerForm.valid" class="login" type="submit">PAY NOW</button>
</form>

  

在此组件中，有时如果表单有效，则无法启用按钮。在android中工作正常。但不适用于ios。