javascript - 从 Web 服务返回单个 json 对象的数组

Question

我正在从 Web 服务检索 json 并使用 $.each() 遍历层次结构。我遇到的问题是“标题”，可能有一个或多个标题。如何强制“Titles”返回对象数组，即使集合中只有一个对象，这样 $.each() 就不会爆炸。

'VB Webservice...
ds.DataSetName = "dsSurveys"
ds.Tables(0).TableName = "Surveys"
ds.Tables(1).TableName = "Titles"
ds.Tables(2).TableName = "Questions"
ds.Tables(3).TableName = "ResponseTypes"

Dim relSurveyTitles As New DataRelation("relSurveyTitles", ds.Tables("Surveys").Columns("SurveyId"), ds.Tables("Titles").Columns("SurveyId"))
Dim relTitlesQuestions As New DataRelation("relTitlesQuestions", ds.Tables("Titles").Columns("TitleId"), ds.Tables("Questions").Columns("TitleId"))
Dim relResponseTypesQuestions As New DataRelation("relResponseTypesQuestions", ds.Tables("ResponseTypes").Columns("ResponseTypeId"), ds.Tables("Questions").Columns("ResponseTypeId"))

relSurveyTitles.Nested = True
relTitlesQuestions.Nested = True
relResponseTypesQuestions.Nested = False

ds.Relations.Add(relSurveyTitles)
ds.Relations.Add(relTitlesQuestions)
ds.Relations.Add(relResponseTypesQuestions)

Dim doc As New XmlDocument()
doc.LoadXml(ds.GetXml())
Dim jsonText As String = JsonConvert.SerializeXmlNode(doc).Replace("null", """""").Replace("'", "'")
Return jsonText

//json response
{
    "dsSurveys": {
        "Surveys": {
            "SurveyId": "1",
            "SurveyName": "Survey 1",
            "Titles": {     //I would like to see this in an array (like "Questions") --> "Titles": [{
                             //regarless of object count
                "SurveyId": "1",
                "TitleId": "1",
                "TitleName": "Title 1",
                "Questions": [{
                    "SurveyId": "1",
                    "TitleId": "1",
                    "QuestionId": "1",
                    "Question": "Question 1?",
                    "isComment": "true",
                    "ResponseTypeId": "1"
                },
                {
                    "SurveyId": "1",
                    "TitleId": "1",
                    "QuestionId": "2",
                    "Question": "Question 2?",
                    "isComment": "true",
                    "ResponseTypeId": "1"
                }]
            }
        },
        "ResponseTypes": {
            "ResponseTypeId": "1",
            "ResponseType": "Yes|No|N/A"
        }
    }
}

Answer 1

查看the documentation ，看来你可以强制Titles通过添加 json:Array='true' 序列化为数组，即使只出现一次属性(其中 json 命名空间为 http://james.newtonking.com/projects/json )到 <Titles>节点。

您可以使用如下方式添加适当的属性:

Dim doc As New XmlDocument()
doc.LoadXml(ds.GetXml())

' Add the namespace declaration to the root node
Dim nsAttr = doc.CreateAttribute("xmlns", "json", "http://www.w3.org/2000/xmlns/")
nsAttr.Value = "http://james.newtonking.com/projects/json"
doc.DocumentElement.Attributes.Append(nsAttr)

' Add the json:Array attribute to each Titles element
For Each title As XmlElement In doc.SelectNodes("//Titles")
    Dim attr = doc.CreateAttribute("json:Array", "http://james.newtonking.com/projects/json")
    attr.Value = "true"
    title.Attributes.Append(attr)
Next

Dim jsonText As String = JsonConvert.SerializeXmlNode(doc).Replace("null", """""").Replace("'", "'")
Return jsonText