您可以使用所谓的事件在它们之间进行通信的一种方式。

一个指令可以在 rootscope 上发出一个事件，然后任何人都可以收听该事件。您可以使用$rootScope.$emit或$rootScope.$broadcast发布带有数据的事件并用于$scope.$on侦听事件。在你的情况下，你也可以这样做$scope.$emit。

app.directive("firstDir", function(){
    return {
        restrict : 'E',
        controller : function($scope){        
            this.data = 'init value';

            this.set = function(value){
             //EMIT THE EVENT WITH DATA
              $scope.$emit('FIRST_DIR_UPDATED', value);
                this.data = value;
                // communication with second Directive ???
            }       
        },
        controllerAs : 'firstCtrl'
    };  
});

app.directive("secondDir", function(){
    return {
        restrict : 'E',
        controller : function($scope){    
          var _that = this;
          //LISTEN TO THE EVENT 
          $scope.$on('FIRST_DIR_UPDATED', function(e, data){
                 _that.data = data;
          });
          this.data = 'init value';   
        },
        controllerAs : 'secondCtrl'
    };  
});

演示 Demo2

____________________________________________________________________________

现在说到这一点，有时确实需要注入$rootScope才能将事件启用到应用程序中的不同节点。相反，您可以在您的应用程序中轻松构建发布/订阅机制，并利用原型继承。

在这里，我将2种方法publish，并subscribe在$rootScope's原型应用程序初始化过程中。因此，任何子作用域或隔离作用域都可以使用这些方法，通信将变得更加容易，无需担心是否使用$emit, $broadcast，是否需要$rootscope从隔离作用域指令中注入用于通信等。

app.service('PubSubService', function () {


   return {Initialize:Initialize};

     function Initialize (scope) {
        //Keep a dictionary to store the events and its subscriptions
        var publishEventMap = {};

         //Register publish events
          scope.constructor.prototype.publish =  scope.constructor.prototype.publish 
           || function () {
                var _thisScope = this,
                    handlers, 
                    args, 
                    evnt;
                //Get event and rest of the data
                args = [].slice.call(arguments);
                evnt = args.splice(0, 1);
                //Loop though each handlerMap and invoke the handler
                angular.forEach((publishEventMap[evnt] || []), function (handlerMap) {
                    handlerMap.handler.apply(_thisScope, args);
                })
            }

         //Register Subscribe events
         scope.constructor.prototype.subscribe = scope.constructor.prototype.subscribe 
            || function (evnt, handler) {
                var _thisScope = this,
                    handlers = (publishEventMap[evnt] = publishEventMap[evnt] || []);

                //Just keep the scopeid for reference later for cleanup
                handlers.push({ $id: _thisScope.$id, handler: handler });
              //When scope is destroy remove the handlers that it has subscribed.  
             _thisScope.$on('$destroy', function () {
                for(var i=0,l=handlers.length; i<l; i++){
                  if (handlers[i].$id === _thisScope.$id) {
                        handlers.splice(i, 1);
                        break;
                    }
                }
            });
        }

    }
}).run(function ($rootScope, PubSubService) {
    PubSubService.Initialize($rootScope);
});

你可以让你的应用程序的任何地方发布一个事件而不需要 rootScope。

$scope.publish('eventName', data);

并听取应用的任何地方，而不必担心使用$rootScope或$emit或$broadcast： -

$scope.subscribe('eventName', function(data){
    //do somthing
});

演示 - 发布订阅

从您的示例中，指令结构不是父子结构。因此你不能通过他们的控制器共享方法。我会使用$rootScope.$broadcast. （见文档）

一个指令调用：

$rootScope.$broadcast('someEvent', [1,2,3]);

第二个指令监听：

 scope.$on('someEvent', function(event, mass) {
    console.log(mass)}
  );

演示 Fiddle

固定指令：

app.directive("firstDir", function ($rootScope) {
    return {
        restrict: 'E',
        link: function (scope, element, attrs) {
            scope.dataToPass = 'empty';
            scope.doClick = function (valueToPass) {
                scope.dataToPass = valueToPass;
                $rootScope.$broadcast('someEvent', {
                    data: valueToPass
                });
            }
        }
    };
});

app.directive("secondDir", function () {
    return {
        restrict: 'E',
        link: function (scope, element, attrs) {
            scope.receivedData = 'none';

            scope.$on('someEvent', function (event, result) {
                scope.receivedData = result.data;
            });
        }
    }
});

我使用的是导出指令控制器。假设我有以下指令：

app.directive('mainDirective', function () {
  return {
    require: 'mainDirective'
    restrict: 'E',
    scope: {
      controller: '='
    },
    controller: [
      '$scope',
      function ($scope) {
        // controller methods
        this.doSomething = function () { ... },

        $scope.controller = this
        return this
      }
    ],
    link: function (scope, element, attrs, mainDirective) {
      // some linking stuff
    }
  }
});

我的 html 看起来像这样：

<main-directive controller="mainDirective"></main-directive>
<sub-directive main-directive="mainDirective"></sub-directive>

如果我想从子指令控制主指令，我可以轻松地从它的范围中获取它并做我想做的任何事情......

app.directive('subDirective', function () {
  return {
    restrict: 'E',
    scope: {
      mainDirective: '='
    }
    link: function (scope, element, attrs) {
      // do something with main directive
      scope.mainDirective.doSomething();
    }
  }
});