ng-src作用，ngsrc

ng-src作用，ngsrc

...<ul class="phones">  <li ng-repeat="phone in $ctrl.phones | filter:$ctrl.query | orderBy:$ctrl.orderProp" class="thumbnail">    <a href="#/phones/{{phone.id}}" class="thumb">      <img ng-src="{{phone.imageUrl}}" alt="{{phone.name}}" />    </a>    <a href="#/phones/{{phone.id}}">{{phone.name}}</a>    <p>{{phone.snippet}}</p>  </li></ul>...

We also added phone images next to each record using an image tag with the ngSrc directive. That directive prevents the browser 
from treating the Angular {{ expression }} markup literally, and initiating a request to an invalid URL 

為什麼不直接使用<img src="{{phone.imageUrl}}">因為瀏覽器會請求{{phone.imageUrl}}這個url。