AngularJS 验证码60秒倒计时功能的实现

<a href="javascript:" rel="external nofollow" ng-click="sendphonecode(reg_phone)" ng-class="paraclass" ng-bind="paracont">获取验证码</a> 

angular.module('controllers', []).controller('registerCtrl', function($scope,$interval){     $scope.paracont = "获取验证码";     $scope.paraclass = "but_null";     $scope.paraevent = true;     var second = 60,       timePromise = undefined;     timePromise = $interval(function(){      if(second<=0){       $interval.cancel(timePromise);       timePromise = undefined;       second = 60;       $scope.paracont = "重发验证码";       $scope.paraclass = "but_null";       $scope.paraevent = true;      }else{       $scope.paracont = second + "秒后可重发";       $scope.paraclass = "not but_null";       second--;      }     },1000,100); });