ng-animate动画实例

http://devdocs.io/angular/nganimate

<div ng-if="bool" class="fade">
   Fade me in out
</div>
<button ng-click="bool=true">Fade In!</button>
<button ng-click="bool=false">Fade Out!</button>
/* The starting CSS styles for the enter animation */
.fade.ng-enter {
  transition:0.5s linear all;
  opacity:0;
}

/* The finishing CSS styles for the enter animation */
.fade.ng-enter.ng-enter-active {
  opacity:1;
}
/* now the element will fade out before it is removed from the DOM */
.fade.ng-leave {
  transition:0.5s linear all;
  opacity:1;
}
.fade.ng-leave.ng-leave-active {
  opacity:0;
}