angularjs中的controller值传递，$emit,$

概念

1. $emit,$broadcast设置值，$on获取值
2. $emit向上传递，$broadcast向下传递

EXAMPLE

• html
  <pre>
  <div ng-controller="ParentController">
  parentCount：{{ count }}
  <div ng-controller="CurentController">
  <button type="button" ng-click="emit()">emit</button>
  <button type="button" ng-click="broadcast()">broadcast</button>
  curentCount：{{ count }}
  <div ng-controller="ChildController">
  childCount：{{ count }}
  </div>
  </div>
  <div ng-controller="BorController">
  borCount：{{ count }}
  </div>
  </div>
  </pre>
• js
  <pre>
  // 父级controller
  .controller('ParentController', function($scope) {
  $scope.count = 0;
  $scope.$on('p-count', function(d, data){
  console.log(data); // emit中保存的值
  $scope.count ++;
  })
  })
  // 使用$emit,$broadcast保存值,可以在父级，子级和本身中取得
  .controller('CurentController', function($scope) {
  $scope.count = 0;
  $scope.emit = function(){
  $scope.count ++;
  // 向父级controller传递值p-count
  $scope.$emit('p-count', $scope.count);
  }
  $scope.broadcast = function(){
  $scope.count = $scope.count + 1;
  // 可以不传第二个args，$on获取时，第二个参数为undefined
  $scope.$broadcast('c-count');
  }
  })
  .controller('ChildController', function($scope){
  $scope.count = 0;
  $scope.$on('c-count', function(d,data){
  console.log(data); // undefined
  $scope.count ++
  })
  })
  // 兄弟controller，不会被影响
  .controller('BorController', function($scope) {
  $scope.count = 0;
  // 下面两个不被触发，回调函数不执行，不输出任何东西
  $scope.$on('p-count', function(d,data){
  console.log(data);
  })
  $scope.$on('c-count', function(d,data){
  console.log(data);
  }
  })
  </pre>