Question

我有一组消息类，它包含代表特定类型消息所需数据的各种子类。当我将字符串反序列化为消息对象时，如果内部XML包含无效，则仍将使用null必需属性创建该对象。我希望它能抛出异常。

这里有一些样本：

<Serializable>
<XmlRoot("INTERFACE")>
Public Class WM_Interface_ISHP
    Inherits WM_Interface

    Private m_Shipments As List(Of WM_Shipment)

    <XmlElement(ElementName:="SHIPMENT", IsNullable:=False)>
    Public Property Shipments() As List(Of WM_Shipment)
        Get
            Return m_Shipments
        End Get
        Set(value As List(Of WM_Shipment))
            m_Shipments = value
        End Set
    End Property
End Class
<Serializable>
Public Class WM_Shipment
    Private m_Ship_ID As String
    Private m_Shipment_Type_CI As String
    Private m_Exp_Ship_DT_CI As String
    Private m_FDD_Flg_CI As String
    Private m_Ship_Lines As List(Of WM_Ship_Line)

    <XmlAttribute("SHIP_ID")>
    Public Property Ship_ID() As String
        Get
            Return m_Ship_ID
        End Get
        Set(value As String)
            m_Ship_ID = value
        End Set
    End Property

    <XmlAttribute("SHIPMENT_TYPE_CI")>
    Public Property Shipment_Type_CI() As String
        Get
            Return m_Shipment_Type_CI
        End Get
        Set(value As String)
            m_Shipment_Type_CI = value
        End Set
    End Property

    <XmlAttribute("EXP_SHIP_DT_CI")>
    Public Property Exp_Ship_DT_CI() As String
        Get
            Return m_Exp_Ship_DT_CI
        End Get
        Set(value As String)
            m_Exp_Ship_DT_CI = value
        End Set
    End Property

    <XmlAttribute("FDD_FLG_CI")>
    Public Property FDD_Flg_CI() As String
        Get
            Return m_FDD_Flg_CI
        End Get
        Set(value As String)
            m_FDD_Flg_CI = value
        End Set
    End Property

    <XmlElement(ElementName:="SHIP_LINE", IsNullable:=False)>
    Public Property Ship_Lines() As List(Of WM_Ship_Line)
        Get
            Return m_Ship_Lines
        End Get
        Set(value As List(Of WM_Ship_Line))
            m_Ship_Lines = value
        End Set
    End Property
End Class

我看到了一些建议，但它们并不适合我：

Data Contract Serializer - 不幸的是我需要能够在序列化期间控制某些东西是属性还是元素，所以这不好。
在反序列化对象后使用使用反射的函数来检查是否标记了isNullable:= False以及它是否为空。如果是这样，抛出异常。不幸的是，这只有在顶级必需属性为null时才有效。

到目前为止我的代码是：

Public Shared Function ValidatingDeserializer(Of T)(s As Stream) As T
    Dim deserialize As T = DirectCast(New XmlSerializer(GetType(T)).Deserialize(s), T)

    For Each pi As PropertyInfo In GetType(T).GetProperties()
        Dim xmlNull As Attribute = pi.GetCustomAttribute(GetType(XmlElementAttribute))
        If xmlNull IsNot Nothing Then
            Dim xmlNullInst As XmlElementAttribute = DirectCast(xmlNull, XmlElementAttribute)
            If xmlNullInst.IsNullable = False And IsNothing(pi.GetValue(deserialize)) = True Then
                Throw New Exception(String.Format("XML Deserialization Error, Message = {0} can't be null.", pi.Name))
            End If
        End If
    Next
    Return deserialize
End Function

在我的示例中，如果未定义任何货件，则应该（并且）触发异常。但如果有shipment但没有ship_lines，则应触发异常，但不是。

除非我绝对必须，否则我宁愿不使用XSD。我想创建一个基于XMlSerializer的自定义XMLSerializer，但会添加一个新的＆＃34;必需＆＃34; XMLElement和XMLAttribute的属性。然后，当我反序列化它时，它会根据修饰的属性值抛出异常。

自定义XMLSerializer

0 个答案: