ion-nav-bar中添加button

http://ionicframework.com/docs/api/directive/ionNavButtons/

Usage

<ion-nav-bar></ion-nav-bar><ion-nav-view>  <ion-view>    <ion-nav-buttons side="left">      <button class="button" ng-click="doSomething()">        I'm a button on the left of the navbar!      </button>    </ion-nav-buttons>    <ion-content>      Some super content here!    </ion-content>  </ion-view></ion-nav-view>