所示的System.Text.JSON.DeserializeAsync JSON对象我的代码未正确发生

问题描述

我正在使用以下数据模型和代码来异步反序列化某些JSON，但是未正确读取根模型的属性。如何解决？

数据模型：

Namespace TestData
    Public Class IDocsAttribute
        Public Property Project_No As String
        Public Property Project_Name As String
        Public Property Deliverable As String
        Public Property Doc_ID As String
        Public Property Doc_No As String
        Public Property Title As String
        Public Property Doc_Type As String
        Public Property Revision As String
        Public Property Issue_State As String
        Public Property FileName As String
        Public Property Supplier_Doc_No As String
        Public Property Supplier_Name As String
        Public Property Originator_RE_Name As String
        Public Property Supplier_Revision As String
        Public Property Return_Date As String
        Public Property Tag_Equipment_No As String
        Public Property Doc_Classification As String
        Public Property SDR_Code As String
        Public Property URL As String
        Public Property Folder_No As String
        Public Property Rev_Ver As String
        Public Property Cur_Ver As String
        Public Property Discipline As String
        Public Property Requisition_PO_No As String
    End Class

    Public Class Root
        Public Property Children As List(Of IDocsAttribute)
    End Class
End Namespace    

反序列化代码：

Private Async Sub IsAvailiable_ClickAsync(sender As Object,e As EventArgs) Handles IsAvailiable.Click
    Try
        Dim oContent1 = New StringContent("")
        Dim response As HttpResponseMessage = Await client.PostAsync("check/",oContent1)
        Dim sReponse As String
        If (response.IsSuccessStatusCode) Then
            sReponse = Await response.Content.ReadAsStringAsync()
        Else
            sReponse = "Failed"
            Exit Sub
        End If
        Dim squote = Chr(34).ToString()
        Dim sbody As String = Requestmessage

        Dim content = New StringContent(sbody)
        response = Await client.PostAsync("document/",content)
        sReponse = Await response.Content.ReadAsStringAsync()

        Using stream As IO.Stream = Await response.Content.ReadAsStreamAsync()                
            Dim filemodules As Root = Await JsonSerializer.DeserializeAsync(Of Root)(stream)
        End Using

    Catch ex As Exception

    End Try
End Sub

以下显示反序列化的JSON格式：

{
   "iDocs_Attribute" : [
     {
      "Project_No" : "236910","Project_Name" : "236910","Deliverable" : "Yes","Doc_ID" : "239585832","Doc_No" : "236910-BAY3-CMC-13101-01-00006","Title" : "E1-E6-22001-01","Doc_Type" : "Supplier Document","Revision" : "1","Issue_State" : "C1-Accepted without Comments","Discipline" : "23.1 - Civil Structural","FileName" : "236910-BAY3-CMC-13101-01-00006.PDF","Supplier_Doc_No" : "1923401907PD-BBS\n-1","Requisition_PO_No" : "CMC-13101-01","Supplier_Name" : "CMC Rebar","Originator_RE_Name" : "Jorge Manrique","Supplier_Revision" : "01","Received_Date" : "11/07/2019","Return_Date" : "11/07/2019","Tag_Equipment_No" : "NO-TAGS","Doc_Classification" : "S2 - Secondary 2","SDR_Code" : "G82 Placing/Marking Drawings and Bar Bending Schedules","URL" : "https://edms-tst.mcdermott.com/edms/redirect/getdocumentf?spec=0,1,239585832,6,557173022","Folder_No" : "G - Detail Drawings","Rev_Ver" : "6","Cur_Ver" : "6"
    }
  ]
}

解决方法

您在这里似乎有两个问题。

首先，您的JSON根属性命名为iDocs_Attribute而不是Children：

{
   "iDocs_Attribute" : [/* Contents omitted */]
}

因此，相应的vb.net属性必须具有相同的名称：

Public Class Root
    Public Property iDocs_Attribute As List(Of IDocsAttribute)
End Class

或者，您可以应用JsonPropertyNameAttribute来通知序列化器正确的名称：

Public Class Root
    <System.Text.Json.Serialization.JsonPropertyName("iDocs_Attribute")> _
    Public Property Children As List(Of IDocsAttribute)
End Class

第二，您的反序列化代码从response.Content 两次中读取：

' Reads the response as a string
sReponse = Await response.Content.ReadAsStringAsync() 

' Reads the response as a Stream
Using stream As IO.Stream = Await response.Content.ReadAsStreamAsync()                
    Dim filemodules As Root = Await JsonSerializer.DeserializeAsync(Of Root)(stream)
End Using

我怀疑您应该只做一个，而不能两个都做。如果要使用异步反序列化，请删除对Await response.Content.ReadAsStringAsync()的第二次调用。