未定义Angularjs$location.path

我正在使用angularJs构建一个应用程序，但控制器中未定义$location.path。每次“未捕获类型错误：$location.path不是函数”时都会出现以下错误

   app.controller('signin', ['$scope', '$http', 'user', '$location', function($scope, $http, $location, user){

      $scope.checkIfEnterKeyWasPressed = function($event){
        var keyCode = $event.which || $event.keyCode;
        if (keyCode === 13) {
            login();
        }
      };
     
      $(document).on('click','#signin', function(){
        // submit button
        login();
      });

      function login(){
        var data = $('#loginform').serialize();
        if (data != 'id=&password=') {
          $.ajax({
            url : api+'auth/',
            method : 'POST',
            data : data,
              success: function(data){
                // user.userLoggedIn();
                // user.setName(data.username);
                // window.location.href = "http://localhost/vivita/pages/admin/#/";
                $location.path("/admin/home/");
              }
          });
        return false;
        }else{
          swal("Warning!", "Password and Id Number is required!", "warning");
        }
      }
    }])