錯誤，當我試圖驗證輸入Angular2

我試圖驗證輸入錯誤，當我試圖驗證輸入Angular2

<md-input-container class="name-input"> 
       <input type="text" mdInput [(ngModel)]="tileName" #tileNameInput="ngModel" 
         id="tileNameInput" name="tileNameInput" 
         required placeholder="{{ 'Name' | translate }}"/> 
       <md-error *ngIf="v.errors.required">Tile Name is required</md-error> 
      </md-input-container>

，我得到了錯誤：

ERROR TypeError: Cannot read property 'errors' of undefined at Object.eval [as updateDirectives] (HeaderComponent.html:104) at Object.debugUpdateDirectives [as updateDirectives] (core.es5.js:12784) at checkAndUpdateView (core.es5.js:12122) at callViewAction (core.es5.js:12485) at execEmbeddedViewsAction (core.es5.js:12443) at checkAndUpdateView (core.es5.js:12123) at callViewAction (core.es5.js:12485) at execComponentViewsAction (core.es5.js:12417) at checkAndUpdateView (core.es5.js:12128) at callViewAction (core.es5.js:12485)

有人能幫助我嗎？

來源

2017-05-30 Max Karpovets