我认为这应该做您想要的:
<button ng-click='activity.seen = !activity.seen'> <span>{{activity.seen ? 'Mark unread' : 'Mark read'}}</span> </button>[**Fiddle**](http://jsfiddle.net/GruffBunny/gNYHt/)

我认为这应该做您想要的:
<button ng-click='activity.seen = !activity.seen'> <span>{{activity.seen ? 'Mark unread' : 'Mark read'}}</span> </button>[**Fiddle**](http://jsfiddle.net/GruffBunny/gNYHt/)