Question

我有一个包装类来帮助反序列化传入的json消息。目前我正在使用它。

Dim oXMessage As XMessage = JsonConvert.DeserializeObject(Of XMessage)(message)

我想为类创建一个构造函数，以便我可以更干净地实例化它。喜欢这个

Dim oXMessage as XMessage = New XMessage(message)

我已经尝试过以下构造函数，但它不起作用。有人能指出我正确的方向吗？

Public Class XMessage
    <JsonProperty("e")> Public MessageType As String
    <JsonProperty("data")> Public MessageData As Object
    <JsonProperty("ok")> Public MessageOk As String

    Public Sub New(message As String)
        Me = JsonConvert.DeserializeObject(Of Me)(message)
    End Sub
End Class

Answer 1

Me关键字引用当前实例，不能作为赋值目标。

相反，您可能想要做的是创建一个新对象，对其进行反序列化，并将新对象成员变量复制到当前实例。

编辑：没有辅助功能

Public Class XMessage

    <JsonProperty("e")> Public MessageType As String
    <JsonProperty("data")> Public MessageData As Object
    <JsonProperty("ok")> Public MessageOk As String

    Public Sub New(message As String)
        Dim other = JsonConvert.DeserializeObject(Of XMessage)(message)
        Me.MessageType = other.MessageType
        Me.MessageData = other.MessageData
        Me.MessageOk = other.MessageOk
    End Sub

End Class

<强>原始

Public Class XMessage

    <JsonProperty("e")> Public MessageType As String
    <JsonProperty("data")> Public MessageData As Object
    <JsonProperty("ok")> Public MessageOk As String


    Public Sub New(message As String)
        Dim other as XMessage= Deserialize(message)
        Me.MessageType = other.MessageType
        Me.MessageData = other.MessageData
        Me.MessageOk = other.MessageOk
    End Sub


    Public shared Function Deserialize(message as String) as XMessage
        return JsonConvert.DeserializeObject(Of XMessage)(message)
    End Function

    Public Shared Function Serialize(message As XMessage) As String 
        return JsonConvert.SerializeObject(message)
    End Function

End Class

Answer 2

您无法在构造函数中重新分配Me的值，因为这是当前正在构造的对象。但您可以致电JsonConvert.PopulateObject()初始化其内容：

Public Class XMessage
    <JsonProperty("e")> Public MessageType As String
    <JsonProperty("data")> Public MessageData As Object
    <JsonProperty("ok")> Public MessageOk As String

    Public Sub New(message As String)
        JsonConvert.PopulateObject(message, Me)
    End Sub

    Public Sub New()
    End Sub
End Class

示例fiddle。

vb.net本身的类构造函数

2 个答案: