Angular:无法使用服务访问控制器中的变量 [英] Angular: Not able to access variables in controller using service

问题描述

我正在尝试在控制器和功能之间共享变量.但是我从控制器收到一个错误，说:

I am trying to share a variable between a controller and a function. But i get an error from the controller, saying this:

TypeError: Cannot read property 'getSet' of undefined 

我已经看过很多教程，但是不知道我要去哪里. 我的服务代码如下:

I have gone through numerous tutorials, but don't know where am I going wrong. My service code is like this:

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

    var selected = ["plz", "print", "something"];

    var putSet = function(set) {
        selected = set;
    };

    var getSet = function() {
        return selected;
    };

    return {
        putSet: putSet,
        getSet: getSet
    };
});   

我可以从这样定义的函数中访问selected:

I am able to reach selected from my function defined like this:

setDisplay = function($scope, $mdDialog, shareData) {

    console.log(shareData.getSet()); // this is working

    $scope.selected = shareData.getSet();
    $scope.hide = function() {
        $mdDialog.hide();
    };
    $scope.cancel = function() {
        $mdDialog.cancel();
    };
    $scope.answer = function(answer) {
        $mdDialog.hide(answer);
    };
};

我的控制器是这样的:

app.controller('topicController', ['$scope', '$http', '$mdDialog', 'shareData',
function ($scope, $http, $mdDialog, $mdToast, shareData) {

    console.log(shareData.getSet()); // NOT WORKING

}]); 

推荐答案

您在topicController控制器的工厂功能中有多余的$mdToast，您需要将其删除.

You had extra $mdToast in your topicController controller's factory function, you need to remove it.

它不起作用的原因是，当前您在数组中提到了4个依赖项，例如['$scope', '$http', '$mdDialog', 'shareData', function&那么您将在DI数组旁边的函数中使用它的实例.在该函数内部，实际上有5个依赖项，其中$mdToast个额外.因此，在幕后发生的事情是，函数$scope持有一个'$scope' DI数组的值，就像您从右到左走一样.但是，当涉及到$mdToast(在控制器功能中)时，它保持的值是'shareData'(DI数组的)，并且那么下一个参数shareData什么也不会得到.

The reason behind it was not working is, currently you had 4 dependency mentioned in array like ['$scope', '$http', '$mdDialog', 'shareData', function & then you are using its instance inside the function next to DI array. Inside that function you had actually 5 dependencies where $mdToast extra. So behind the scene what happening is $scope of function hold an value of '$scope' DI array likewise you go right to left. But when it comes to $mdToast(in controller function) it was holding a value of 'shareData'(of DI array) & then the next parameter shareData get nothing.

app.controller('topicController', ['$scope', '$http', '$mdDialog', 'shareData', 
      function ($scope, $http, $mdDialog, shareData) { //<--removed $mdToast
    console.log(shareData.getSet());
  }
]);

注意::您正在使用 DI内联数组注释，因此在数组中注入依赖项的顺序，应该以相同的顺序 然后注入基础工厂功能.

NOTE: You are using DI inline array annotation, so the sequence in which dependency are injected in array, in same sequence you should inject then in underlying factory function.

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