Question

我正在尝试将控制器中的变量设置为函数的返回值。此函数在表中创建一个新条目，然后返回其id。当我在chrome开发人员工具中调试时，我可以看到我的函数正常工作，response.data实际上是一个数字。但是，当我尝试将变量设置为此函数调用时，该值将设置为undefined。

我的AngularJS组件：

function saveNewGame($http, gameData) {

    var newGameData = {
        "InvestigatorGroupUserId": gameData.GroupUserId,
        "InvestigatorGroupGameId": gameData.GroupGameId,
        "WithTeacher": gameData.WithTeacher
    };

    $http.post("/APGame.WebHost/play/newGamePlayed", newGameData)
        .then(function(response) {
            return response.data;
        });

}

function controller($http) {

    var model = this;
    var gameData = model.value;
    var gamePlayedId;

    model.startGame = function() {
        gamePlayedId = saveNewGame($http, gameData);
        alert(gamePlayedId);
    };
}

module.component("gameApp",
{
    templateUrl: "/APGame/GameAngular/game-app.html",
    controllerAs: "game",
    bindings: {
        value: "<"
    },
    controller: ["$http", controller]
});

这就是我的服务电话：

    [OperationContract]
    [WebInvoke(Method = "POST", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json, UriTemplate = "newGamePlayed")]
    int NewGamePlayed(GamePlayedData gamePlayedData);



    public int NewGamePlayed(GamePlayedData gamePlayedData)
    {
        var gamePlayedRepo = _gamePlayedRepo ?? new GamePlayedRepository();

        var newGame = new GamePlayed()
        {
            InvestigatorGroupUserId = gamePlayedData.InvestigatorGroupUserId,
            InvestigatorGroupGameId = gamePlayedData.InvestigatorGroupGameId,
            GameStartTime = DateTime.Now,
            IsComplete = false
        };

        return gamePlayedRepo.Create(newGame);
    }

Answer 1

将promise promisement listener添加到方法调用中，如下所示：

model.startGame = function() {
    gamePlayedId = saveNewGame($http, gameData)then(function(response) {
      alert(response.data);
    }, function(reason) {
      alert('Failed: ' + reason);
    });
};

返回http.get承诺而不是数据

function saveNewGame($http, gameData) {

    var newGameData = {
        "InvestigatorGroupUserId": gameData.GroupUserId,
        "InvestigatorGroupGameId": gameData.GroupGameId,
        "WithTeacher": gameData.WithTeacher
    };

    return $http.post("/APGame.WebHost/play/newGamePlayed", newGameData);
}

Answer 2

原因是因为你的函数没有返回任何未定义的值。

$http.post("/APGame.WebHost/play/newGamePlayed", newGameData)
    .then(function(response) {
        // notice that you are returning this value to the function(response) not your saveNewGame function
        return response.data;
    });

由于javascript的异步性，你应该做一些相反的事情。 $ http.post返回一个promise对象，可以像下面一样使用。

return $http.post("/APGame.WebHost/play/newGamePlayed", newGameData);

在你的通话功能中。

saveNewGame($http, gameData).then(function(response){
    gamePlayedId = response.data;
});

设置javascript变量以返回函数的值

2 个答案: