javascript - 单击提交按钮时 Angular 7 表单验证不显示错误

Question

我正在尝试使用 Angular 7 Form Validation 实现重置密码表单作为 here 中的示例.在这个例子中，我们有三个字段，分别是旧密码、新密码和确认密码。如果我单击一个输入字段，例如没有输入任何值的旧密码字段，然后单击另一个输入字段，例如新密码字段，我将能够看到一条来自验证的错误消息。但是，如果我不触摸三个输入字段中的任何一个并直接单击更新，则不会显示任何错误。如何实现点击按钮时显示每个输入字段验证错误的功能？

Answer 1

您只需用表单标签替换您的 div 包装器。

stackblitz

<form id='reset-password' [formGroup]='formGroup'>
  <mat-form-field class="reset-password-fields">
    <input matInput required [(ngModel)]="oldPassword" [type]="displayOldPassword ? 'text' : 'password'"
      autocomplete="off" [formControl]="oldPasswordFormControl" [errorStateMatcher]="appErrorMatcher" required>
    <mat-placeholder class="placeholder" color="primary">{{ 'enter-your-old-password' }}</mat-placeholder>
    <mat-icon matSuffix (click)="displayOldPassword = !displayOldPassword">
      {{displayOldPassword ? 'visibility' : 'visibility_off'}}</mat-icon>
    <mat-error *ngIf="oldPasswordFormControl.hasError('required')">
      Old password cannot be
      <strong>empty</strong>
    </mat-error>
  </mat-form-field>
  <mat-form-field class="reset-password-fields">
    <input matInput required [(ngModel)]="newPassword" [type]="displayNewPassword ? 'text' : 'password'"
      autocomplete="off" [formControl]="newPasswordFormControl" [errorStateMatcher]="appErrorMatcher" required>
    <mat-placeholder class="placeholder" color="primary">{{ 'enter-your-new-password' }}</mat-placeholder>
    <mat-icon matSuffix (click)="displayNewPassword = !displayNewPassword">
      {{displayNewPassword ? 'visibility' : 'visibility_off'}}</mat-icon>
    <mat-error *ngIf="newPasswordFormControl.hasError('required')">
      New password cannot be
      <strong>empty</strong>
    </mat-error>
  </mat-form-field>
  <mat-form-field class="reset-password-fields">
    <input matInput required [(ngModel)]="confirmNewPassword" [type]="displayConfirmNewPassword ? 'text' : 'password'"
      autocomplete="off" [formControl]="confirmNewPasswordFormControl" [errorStateMatcher]="appErrorMatcher" required>
    <mat-placeholder class="placeholder" color="primary">{{ 'confirm-your-new-password' }}
    </mat-placeholder>
    <mat-icon matSuffix (click)="displayConfirmNewPassword = !displayConfirmNewPassword">
      {{displayConfirmNewPassword ? 'visibility' : 'visibility_off'}}</mat-icon>
    <mat-error *ngIf="formGroup.invalid">
      Confirm new password does not match password
    </mat-error>
  </mat-form-field>
  <div>
    <button (click)='update()' mat-flat-button color="primary">Update</button>
  </div>
</form>

但是如果表单组无效，您也可以通过禁用按钮来解决您的问题:

<button [disabled]="formGroup.invalid" (click)='update()' mat-flat-button color="primary">Update</button>

祝一切顺利