小编Aka*_*yay的帖子

      <form [formGroup]="accountDetailsForm" novalidate (ngSubmit)="onSubmitAccountDetails(accountDetailsForm.value)">

        <mat-form-field class="full-width">
          <input matInput maxlength="25" placeholder="Username" formControlName="username" required>
          <mat-error *ngFor="let validation of account_validation_messages.username">
            <mat-error class="error-message" *ngIf="accountDetailsForm.get('username').hasError(validation.type) && (accountDetailsForm.get('username').dirty || accountDetailsForm.get('username').touched)">{{validation.message}}</mat-error>
          </mat-error>
        </mat-form-field>

        <mat-form-field class="full-width">
          <input matInput type="email" placeholder="Email" formControlName="email" required>
          <mat-error *ngFor="let validation of account_validation_messages.email">
            <mat-error class="error-message" *ngIf="accountDetailsForm.get('email').hasError(validation.type) && (accountDetailsForm.get('email').dirty || accountDetailsForm.get('email').touched)">{{validation.message}}</mat-error>
          </mat-error>
        </mat-form-field>


        <div formGroupName="matching_passwords">
          <mat-form-field class="full-width">
            <input matInput type="password" placeholder="Password" formControlName="password" required>
            <mat-error *ngFor="let validation of account_validation_messages.password">
              <mat-error class="error-message" *ngIf="accountDetailsForm.get('matching_passwords').get('password').hasError(validation.type) && (accountDetailsForm.get('matching_passwords').get('password').dirty || accountDetailsForm.get('matching_passwords').get('password').touched)">{{validation.message}}</mat-error>
            </mat-error>
          </mat-form-field> …