当从服务接收到JSON时，将其删除为null

Question

我有一个对象，我希望发送到一个WCF服务，但对象没有得到正确的转换，以在另一边使用的ActiveFarmer和Evidence总是空的。我用硬编码的JSON对它进行了测试，它可以工作，但击倒对象没有正确通过，对象如下

 self.afi = {

    ActiveFarmer: {
        ActiveFarmerID: ko.observable(),
        BusinessID: ko.observable(),
        Year: ko.observable(),
        StatusID: ko.observable(),
        Status:ko.observable(),
        DecisionDate: ko.observable(),
        UserID: ko.observable(""),         
        DateModified: ko.observable(),

       // RowStatus: ko.observable(""),
    },
    // TODO - RH we used to add a default empty new line here...
    ActiveFarmerEvidence: ko.observableArray(),
    NotepadIdentifiers: ko.observableArray()
};

我正在调用wcf服务

public int UpdateFarmerInfo(ActiveFarmerInfo afi)
{
    return ActiveFarmerInfoManager.UpdateFarmerInfo(afi);
}

我的ajax调用如下

 var afi = vm.afi;
    $.ajax({
        type: "POST",
        contentType: "application/json",
        url: rootcap + "ActiveFarmerService.svc/rest/UpdateFarmer",                                
        data: JSON.stringify(afi),
        dataType: "json",
        async: true,
        cache: false,
        success: function (data, textStatus) {
            self.populateFarmerDetails(data);

        },
        error: function (data, status, error) { }
    });

整个视图模型

function ActiveFarmerModel() {
var self = this;

self.businessId = ko.observable();
self.individualId = ko.observable();
self.currentAppId = ko.observable();
self.userId = ko.observable();
self.evidenceCategories = ko.observableArray();
self.activeFarmerEvidenceCategories = ko.observableArray();
self.businessStatus = ko.observableArray([{ "intStatusID": "2", "vcrStatus": "Provisionally Non-Oct" }, { "intStatusID": "1", "vcrStatus": "Active" }, { "intStatusID": "3", "vcrStatus": "Negative List" }, { "intStatusID": "4", "vcrStatus": "Active (Non Verified)" }])
self.currentStatus = ko.observable();
self.oldStatus = self.currentStatus();
self.ActiveFarmerID = ko.observable();
self.currentYear = ko.observable();
self.years = ko.observableArray([{ "intYearID": "5", "year": "2014" }, { "intYearID": "6", "year": "2015" }]);
self.businessStartDate = ko.observable();
self.DateFromServer = ko.observable(moment(new Date()).format('L')),
self.individualDOB = ko.observable();
self.businessName = ko.observable();
self.countyOfficeId = ko.observable();
self.individualDetails = ko.observable();
self.indDobOuterHTML = ko.observable();

self.evidenceTypes = ko.observableArray();
self.evidenceItem = function (evidenceData) {
    var self = this;
    if (evidenceData === null) {
        self.EvidenceCategoryID = ko.observable(-1);
        self.DateModified = ko.observable(moment(new Date()).format('L'));
        self.DateReceipted = ko.observable(moment(new Date()).format('L'));
        self.DocReceiptID = ko.observable("");
        self.EvidenceID = ko.observable(-1);
        self.EvidenceTypeID = ko.observable(-1);
        self.Other = ko.observable("");
        self.ReceiptedBy = ko.observable("");
        //self.RowStatus = ko.observable("I");
        self.TrimRecord = ko.observable("");
        self.TrimRecordDocReceipt = ko.observable("");
        self.UserID = ko.observable('NIGOV1284535');
        self.selectedCategory = ko.observable(6);
    }
    else {
        self.EvidenceCategoryID = ko.observable(6);
        self.DateModified = ko.observable(moment(evidenceData.DateModified).format('L'));
        self.DateReceipted = ko.observable(moment(evidenceData.DateReceipted).format('L'));
        self.DocReceiptID = ko.observable(evidenceData.DocReceiptID);
        self.EvidenceID = ko.observable(evidenceData.EvidenceID);
        self.EvidenceTypeID = ko.observable(evidenceData.EvidenceTypeID);
        self.Other = ko.observable(evidenceData.Other);
        self.ReceiptedBy = ko.observable(evidenceData.ReceiptedBy);
        self.RowStatus = ko.observable(evidenceData.RowStatus);
        self.TrimRecord = ko.observable(evidenceData.TrimRecord);
        self.TrimRecordDocReceipt = ko.observable(evidenceData.TrimRecordDocReceipt);
        self.UserID = ko.observable(evidenceData.UserID);
        self.selectedCategory = ko.observable(6)
    }
    self.filteredSubCategories = ko.computed(function () {
        self.EvidenceCategoryID = self.selectedCategory();
        var ret = ko.observableArray();
        var filterAll = ko.observableArray();
        ret().push({ EvidenceTypeID: -1, EvidenceTypeDescription: "Please Select..." });
        if (self.selectedCategory()) {
            filterAll = ko.utils.arrayFilter(vm.evidenceTypes(), function (item) {
                return item.EvidenceCategoryID === self.selectedCategory();
            });
            for (var i = 0; i < filterAll.length; i++) {
                ret().push(
                {
                    EvidenceTypeID: filterAll[i].EvidenceTypeID,
                    EvidenceTypeDescription: filterAll[i].EvidenceTypeDescription,
                    EvidenceCategoryID: filterAll[i].EvidenceCategoryID
                });
            };
            return ret();
        }
        return [];
    }, self);
};

self.NotePad = {
    notes: ko.observableArray([
    { DateOfEntry: "01/05/2014", UserName: "John", EntryType: "Change Status", NoteText: "Status Changes to Active(Non Verified)" }
    ])
};
// Active Farmer Information
self.afi = {

    ActiveFarmer: {
        ActiveFarmerID: ko.observable(),
        BusinessID: ko.observable(),
        Year: ko.observable(),
        StatusID: ko.observable(),
        Status:ko.observable(),
        DecisionDate: ko.observable(),
        UserID: ko.observable(),         
        DateModified: ko.observable(),

    },

    ActiveFarmerEvidence: ko.observableArray(),
    NotepadIdentifiers: ko.observableArray()
};

}

 public class ActiveFarmerInfo 
{
    public ActiveFarmerInfo()
    {
    }
    protected override string GetSchemaName()
    {
        return "ActiveFarmer";
    }
    [XmlIgnore]

    public int ActiveFarmerID { get; set; }
    [DataMember, XmlElement]
    public ActiveFarmer ActiveFarmer { get; set; }
    // To contain the list for Active Farmer Application Evidences based on Active Farmer Id and Year
    [DataMember, XmlElement]
    public List<Evidence> ActiveFarmerEvidence { get; set; }
    public Int32 BusinessId { get; set; }
    public Int32 Year { get; set; }

}

Answer 1

视图模型的所有属性都是knockout可观察函数。所以调用JSON.stringify到一个视图模型用那种属性不会产生有效的json。尝试将JSON.strngify更改为ko.toJSON这个函数从knockout视图模型产生有效的json字符串。像这样:

var afi = vm.afi;
$.ajax({
    type: "POST",
    contentType: "application/json",
    url: rootcap + "ActiveFarmerService.svc/rest/UpdateFarmer",                                
    data: ko.toJSON(afi),
    dataType: "json",
    async: true,
    cache: false,
    success: function (data, textStatus) {
        self.populateFarmerDetails(data);

    },
    error: function (data, status, error) { }
});

注意传递给$.ajax函数的对象的data属性