我的应用程序中有2个列表，用户应该将项目从一个列表拖放到另一个列表 当用户将一个元素从一个列表中删除到另一个列表时，必须向服务器端代码发出请求以更新数据库中的字段（SelectedForDiscussion）。 这是我的控制器中的代码：
$scope.$watch("questionsDiscuss", function (value) {
var question = $.Enumerable.From($scope.questionsDiscuss).Where(function (item) { return !item.SelectedForDiscussion }).FirstOrDefault()
if (question != undefined) {
questionSelectionService.UpdateQuestionSelectionStatus(question.Id, true)
.then(function (output) {
var question = $.Enumerable.From($scope.questionsDiscuss)
.Where(function (item) { return item.Id == output.data.questionId })
.FirstOrDefault();
var index = $.Enumerable.From($scope.questionsDiscuss).IndexOf(question);
if (question != undefined)
if (output.data.result != "success") {
$scope.questionsDiscuss.splice(index, 1);
$scope.questionsReceived.splice(0, 0, question);
}
else {
question.SelectedForDiscussion = true;
$scope.questionsDiscuss[index] = question;
}
});
}
else {
var question = $.Enumerable.From($scope.questionsReceived).Where(function (item) { return item.SelectedForDiscussion }).FirstOrDefault();
if (question != undefined) {
questionSelectionService.UpdateQuestionSelectionStatus(question.Id, false)
.then(function (output) {
var question = $.Enumerable.From($scope.questionsReceived)
.Where(function (item) { return item.Id == output.data.questionId })
.FirstOrDefault();
var index = $.Enumerable.From($scope.questionsReceived).IndexOf(question);
if (question != undefined)
if (output.data.result != "success") {
$scope.questionsReceived.splice(index, 1);
$scope.questionsDiscuss.splice(0, 0, question);
}
else {
question.SelectedForDiscussion = false;
$scope.questionsReceived[index] = question;
}
});
}
}
}, true);
我在Firebug中的以下行中放置了4个javascript断点：
其中2个在以下几行：
if (question != undefined) {
一个在：
var question = $.Enumerable.From($scope.questionsDiscuss)
.Where(function (item) {
return item.Id == output.data.questionId
})
.FirstOrDefault();
另一个在：
var question = $.Enumerable.From($scope.questionsReceived)
.Where(function (item) {
return item.Id == output.data.questionId
})
.FirstOrDefault();
发生以下情况：
断点位于：
if (question != undefined) {
。
处的断点
var question = $.Enumerable.From($scope.questionsDiscuss)
.Where(function (item) {
return item.Id == output.data.questionId
})
.FirstOrDefault();
也到了。
另一个从未到达。
两个响应都没问题（响应代码200）
一切都应该完美，但第二个承诺中的第二个条款永远不会达到
谁能告诉我我做错了什么？
服务器端应用程序是一个用C＃编写的ASP.NET MVC应用程序。
编辑1： 我弄清楚为什么会这样，我有一个解决方法。我对实际解决方案感兴趣 问题是angularjs抛出一个错误，然后在第二次调用$ http时吞下它。错误是：
消化正在进行中的
我认为这是因为在我的指令中我有这段代码：
dndfunc = function (scope, element, attrs) {
// contains the args for this component
var args = attrs.dndBetweenList.split(',');
// contains the args for the target
var targetArgs = $('#' + args[1]).attr('dnd-between-list').split(',');
// variables used for dnd
var toUpdate;
var target;
var startIndex = -1;
// watch the model, so we always know what element
// is at a specific position
scope.$watch(args[0], function (value) {
toUpdate = value;
}, true);
// also watch for changes in the target list
scope.$watch(targetArgs[0], function (value) {
target = value;
}, true);
// use jquery to make the element sortable (dnd). This is called
// when the element is rendered
$(element[0]).sortable({
items: 'div',
start: function (event, ui) {
// on start we define where the item is dragged from
startIndex = ($(ui.item).index());
},
stop: function (event, ui) {
var newParent = ui.item[0].parentNode.id;
// on stop we determine the new index of the
// item and store it there
var newIndex = ($(ui.item).index());
var toMove = toUpdate[startIndex];
// we need to remove him from the configured model
toUpdate.splice(startIndex, 1);
if (newParent == args[1]) {
// and add it to the linked list
target.splice(newIndex, 0, toMove);
} else {
toUpdate.splice(newIndex, 0, toMove);
}
// we move items in the array, if we want
// to trigger an update in angular use $apply()
// since we're outside angulars lifecycle
scope.$apply(targetArgs[0]);
scope.$apply(args[0]);
},
connectWith: '#' + args[1]
})
}
最后有2个电话适用，我认为会引发一个新的摘要周期 无论如何，我通过在应用调用之前添加此调用来修复它：
if (scope.updateLists != undefined)
scope.updateLists();
并将手表中的所有代码移动到updateLists函数中。
另外因为人们提到服务与它有关，我在其中粘贴相关代码：
GetQuestionsReceived: function (eid, criteria, page, rows) {
var promise = this.GetQuestionsReceivedInternal(eid,criteria, page, rows).then(function (response) {
// The return value gets picked up by the then in the controller.
return response;
});
// Return the promise to the controller
return promise;
},
GetQuestionsReceivedInternal: function (eid, criteria, page, rows) {
return $http({ method: 'GET',
url: '../QuestionManagement/GetQuestions?eventId='+eid+'&page=1&rows=5&'+serialize(criteria)
}).
success(function (data, status, headers, config) {
// this callback will be called asynchronously
// when the response is available
results = data;
}).
error(function (data, status, headers, config) {
// called asynchronously if an error occurs
// or server returns response with an error status.
if (window.console && console.log) {
console.log("Could not obtain questions received. Error:" + data + "Status:" + status + "Headers:" + headers + "Config:" + config);
}
});
},
GetQuestionsDiscuss: function (eid,criteria, page, rows) {
var promise = this.GetQuestionsDiscussInternal(eid,criteria, page, rows).then(function (response) {
// The return value gets picked up by the then in the controller.
return response;
});
// Return the promise to the controller
return promise;
},
GetQuestionsDiscussInternal: function (eid,criteria, page, rows) {
return $http({ method: 'GET',
url: '../QuestionManagement/GetQuestions?eventId=' + eid + '&page=1&rows=5&' + serialize(criteria)
}).
success(function (data, status, headers, config) {
// this callback will be called asynchronously
// when the response is available
response = data;
}).
error(function (data, status, headers, config) {
// called asynchronously if an error occurs
// or server returns response with an error status.
if (window.console && console.log) {
console.log("Could not obtain questions received. Error:" + data + "Status:" + status + "Headers:" + headers + "Config:" + config);
}
});
},
答案 0 :(得分：0)
你有两个非常相似的代码块，它们可以通用化并放在一个函数包装器中，留下一个非常简单的调用函数。
如果您可以将所有内容都放入该表单中，那么我认为您会发现调试更容易。
尝试这样做：
function updateSelectionStatus(qA, qB, bool) {
var en = $.Enumerable.From(qA);
var question = en.Where(function (item) {
return bool ? !item.SelectedForDiscussion : item.SelectedForDiscussion;
}).FirstOrDefault();
if(question) {
questionSelectionService.UpdateQuestionSelectionStatus(question.Id, bool).then(function (output) {
if (output.data.result == "success") {
question.SelectedForDiscussion = bool;
}
else {
qA.splice(en.IndexOf(question), 1);
qB.unshift(question);
}
});
}
return question;
}
$scope.$watch("questionsDiscuss", function (value) {
if (!updateSelectionStatus($scope.questionsDiscuss, $scope.questionsReceived, true) {
updateSelectionStatus($scope.questionsReceived, $scope.questionsDiscuss, false);
}
}, true);
我可能做了一些错误的假设并且简化了太多（例如，清除内部$.Enumerable.From，这似乎重新选择了与外部相同的问题），因此您可能需要重新编写我的代码。
我在这里提倡一个原则，而不是提供解决方案。