问题
I want to add star button on navigation bar and when user press on this, the button show selected icon and next time is press it show unselected. I tried it by using ionic-on and ionic-off but I can't make it.
回答1:
The icon-on and icon-off attributes only apply to tabs I think. You can use ng-class like you see here. Based on the value of your $scope.starred property, it will show a star or the outline of a star.
<span class="icon" ng-class="{'ion-ios-star': starred, 'ion-ios-star-outline': !starred}"></span>
来源：https://stackoverflow.com/questions/29841253/how-to-adding-navigation-bar-button-having-ionic-on-ionic-off-functionality