我正在尝试使用VB.NET 2.0反序列化JSON字符串

Question

我正在尝试反序列化JSON字符串并卡住。

我的绳子是

[{"BasketItemID":3,"ProductEmbellishmentID":8,"EmbellishmentText":"lfo","Price":9.95},{"BasketItemID":3,"ProductEmbellishmentID":3,"EmbellishmentText":"rc","Price":9.95}]

我已将其保存在琴弦中

我的课是

Public Class Embellishments
Private _BasketItemID As Integer
Private _ProductEmbellishmentID As Integer
Private _EmbellishmentText As Integer
Private _Price As Integer


Public Property BasketItemID() As Integer
    Get
        Return _BasketItemID
    End Get

    Set(value As Integer)
        _BasketItemID = value
    End Set
End Property
Public Property ProductEmbellishmentID() As String
    Get
        Return _ProductEmbellishmentID
    End Get
    Set(value As String)
        _ProductEmbellishmentID = value
    End Set
End Property
Public Property EmbellishmentText() As String
    Get
        Return _EmbellishmentText
    End Get
    Set(value As String)
        _EmbellishmentText = value
    End Set
End Property
Public Property Price() As Decimal
    Get
        Return _Price
    End Get
    Set(value As Decimal)
        _Price = value
    End Set
End Property

最终班

我尝试反序列化使用

        Dim jss As New JavaScriptSerializer()
        Dim emblist As List(Of Embellishments) = jss.Deserialize(Of Embellishments)(embels)

但是出现错误“类型”值的值不能转换为“ System.Collections.Generic.List（Of Embellishments）”

我现在被困住了。 谁能给我任何指示？ 谢谢

编辑

感谢@Plutonix我现在尝试了

    Dim errormessage As String=''
Dim Count As Integer = 0
Try
    Dim jss As New JavaScriptSerializer()
    Dim emblist As List(Of Embellishments) = jss.Deserialize(Of List(Of Embellishments))(embels)

    For Each em As Embellishments In emblist
        Count = Count + 1
    Next

Catch ex As Exception

    errormessage = ex.Message

End Try

我收到错误“调用的目标已抛出异常”

Answer 1

问题是这样的：

Dim emblist As List(Of Embellishments) = jss.Deserialize(Of Embellishments)(embels)

您要告诉Deserializer它正在对Embellishments对象起作用，但试图将结果捕获到集合对象中。 错误消息告诉您，如果您说字符串是单个对象，则无法将其反序列化为它们的列表。 换句话说， Embellishments与List(of Embellishments)是不同的东西。

由于在字符串中的多个对象，正确的语法是（我叫我的Basket ）：

Dim emblist = jss.Deserialize(Of List(Of Basket))(embels)

在VS2010及更高版本中，可以使用Option Infer分配类型。 这也是有效的，并将创建一个购物篮项目数组：

Dim emblist = jss.Deserialize(Of Basket())(embels)

更重要的是，您应该启用Option Strict。 这导致废话：

Private _ProductEmbellishmentID As Integer
Public Property ProductEmbellishmentID() As String

支持字段Type与属性Getter / Setter type不匹配，将导致混乱。 更改Property语句以匹配专用后备字段的类型。 同样，在VS2010之后，您可以使用自动实现属性来减少所有样板代码：

Public Class Basket
    Public Property BasketItemID As Integer
    Public Property ProductEmbellishmentID As Integer
    Public Property EmbellishmentText As String
    Public Property Price As Decimal

End Class