为什么我的诺言不能在angular js中工作？

Question

Below is my angular controller but in it, my promise doesn't seem to work. console.log isn't showing response nor is alert being shown over here.

myapp.controller('contrl6', ['$scope','$q','$localStorage','$http',
  function ($scope,$q,$localStorage,$http) {

    $scope.myXhr = function(){

    var q = $q.defer();

     $http({
        method: 'GET',
         url: '/api/session_data'
        })
        .success(function(response){
            console.log(response);
            q.resolve('request successful');
        })
        .error(function(response){
          console.log("error");
            q.reject('ERROR');
        });


    return q.promise;
}
console.log("hi");

var myPromise = $scope.myXhr();
  myPromise.then(function(resolve){
        alert(resolve);
        console.log(resolve);
        }, function(reject){
        alert(reject);
        console.log(reject);      
    });


  }]);

Answer 1

Inside myxhr nothing is wired together with the result of $http . Don't worry about creating a new promise, because $http already returns one:

$scope.myXhr = function(){

 return $http({
    method: 'GET',
     url: '/api/session_data'
    })
    .then(function(response){
        return response;
    })
    .catch(function(response){
        throw new Error('ERROR');
    });
}

Answer 2

Deprecation Notice

The $http legacy promise methods .success and .error have been deprecated. Use the standard .then method instead. ¹

$scope.myXhrPromise = function(){
    return (
        $http({
            method: 'GET',
            url: '/api/session_data'
        }).then (function onFulfilled (response) {
            console.log(response.data);
            //return data for chaining
            return response.data;
        }).catch (function onRejected (response) {
            console.log(response.status);
            //throw to chain rejection
            throw response;
        })
    );
};

Answer 3

I copy/pasted your code into a Plunkr and it works just fine once I wire it up correctly.

Plunkr example here

As Duncan says, make sure you wire it up correctly, using ng-app and ng-controller. If you can update your question with the HTML markup you're using perhaps we can help further.