<div ng-controller="ParentCtrl">        <!--父级-->
  <div ng-controller="SelfCtrl">       <!--自己-->
    <a ng-click="click()">click me</a>
    <div ng-controller="ChildCtrl"></div>  <!--子级-->
  </div>
  <div ng-controller="BroCtrl"></div>     <!--平级-->
</div>

app.controller('SelfCtrl', function($scope) {
  $scope.click = function () {
    $scope.$broadcast('to-child', 'child');
    $scope.$emit('to-parent', 'parent');
  }
});

app.controller('ParentCtrl', function($scope) {
  $scope.$on('to-parent', function(event,data) {
    console.log('ParentCtrl', data);    //父级能得到值
  });
  $scope.$on('to-child', function(event,data) {
    console.log('ParentCtrl', data);    //子级得不到值
  });
});

app.controller('ChildCtrl', function($scope){
  $scope.$on('to-child', function(event,data) {
    console.log('ChildCtrl', data);     //子级能得到值
  });
  $scope.$on('to-parent', function(event,data) {
    console.log('ChildCtrl', data);     //父级得不到值
  });
});

app.controller('BroCtrl', function($scope){ 
  $scope.$on('to-parent', function(event,data) { 
    console.log('BroCtrl', data);     //平级得不到值 
  }); 
  $scope.$on('to-child', function(event,data) { 
    console.log('BroCtrl', data);     //平级得不到值 
  }); 
});