在表单提交所需的文件不会以红色突出显示

Question

angular4的新手再次陷入了新的情景。我有一个表单和内部，我写了一个对话框内容，如下所示：

<form #f="ngForm" (ngSubmit)="onCloseConfirm(f.value)">
  <md-dialog-content>
  <md-grid-list cols="12" rowHeight="70px">
      <md-grid-tile [colspan]="6" [rowspan]="1">
        <md-input-container>
          <input mdInput placeholder="App Name" value="{{ data.appName }}">
        </md-input-container>
      </md-grid-tile>
      <md-grid-tile [colspan]="6" [rowspan]="1">
          <md-input-container>
            <input mdInput placeholder="App ID" value="{{ data.appID }} ">
          </md-input-container>
        </md-grid-tile>
      <md-grid-tile [colspan]="6" [rowspan]="1">
        <md-input-container>
          <input mdInput ngModel required name="customer" 
#customer="ngModel" placeholder="Customer" >
        </md-input-container>
      </md-grid-tile>
</md-grid-list>
  </md-dialog-content>
  </form>
  <md-dialog-actions>
    <button md-raised-button type="submit" class="saveBTN" >Save</button>
  </md-dialog-actions>

问题是当我点击保存时，它应该显示红色所需的字段，这不会发生。任何人都可以帮助我。