1. 父controller，负责监听并广播

    //监听：若收到change，把值广播出去
    $scope.$on(“change",function (event, msg) {
        $scope.$broadcast(“changeFromBody", msg);
    });
   

2. 子controller，负责把变量发给父controller

    //向父controller传值$scope.value
    $scope.$emit(“change", $scope.value);
   

3. 子controller，负责监听父controller的广播，给变量赋新值

    //监听父controller的广播，得到changeFromBody广播时取$scope.value
    $scope.$on(“changeFromBody",function (event, msg) {
        $scope.value = msg;
    });
   

参考：http://www.cnblogs.com/whitewolf/archive/2013/04/16/3024843.html