Question

我创建了以下自定义类来处理特定字符串（“YYY-MM-DD”）作为动态今日值的表示。有一些扩展，缩小和ToString函数可以帮助程序员进行代码转换。

我的问题是当我反序列化时，使用XmlSerializer，一个使用MyDateTime的类。我虽然XmlSerializer会使用Narrowing Operator CType(rightSide As String) As MyDateTime作为对象初始值设定项，但在重新编译它之前它会使用反射。

如果我希望使用Narrowing Operator CType(rightSide As String) As MyDateTime启用MyDateTime的xml反序列化类属性，我该怎么办？

Public Class MyDateTime

Const cstUniversalTodayValue As String = "YYYY-MM-DD"

Dim _internalStringRepresentation As String
Dim _internaValue As MyDateTime

Public ReadOnly Property DynamicToday As Boolean
    Get
        Return _internalStringRepresentation = cstUniversalTodayValue
    End Get
End Property

Public Shared Widening Operator CType(rightSide As MyDateTime) As MyDateTime

    Return rightSide._internaValue
End Operator
Public Shared Widening Operator CType(rightSide As MyDateTime) As String

    Return rightSide._internalStringRepresentation
End Operator

Public Shared Narrowing Operator CType(rightSide As MyDateTime) As MyDateTime

    Return New MyDateTime With {._internalStringRepresentation = rightSide.ToString("yyyy-MM-dd"), ._internaValue = rightSide}
End Operator
Public Shared Narrowing Operator CType(rightSide As String) As MyDateTime

    Dim instance = New MyDateTime With {._internalStringRepresentation = rightSide}
    If instance.DynamicToday Then

        instance._internaValue = DateTime.Today
    Else

        instance._internaValue = Convert.ToDateTime(rightSide)
    End If

    Return instance
End Operator

Public Overrides Function ToString() As String
    Return Me
End Function
Public Overloads Function ToString(format As String) As String

    Return _internaValue.ToString(format)
End Function
End Class

Answer 1

XmlSerializer不使用类型转换。只需使用sgen工具为您的类型生成序列化程序集，然后通过Reflector浏览生成的代码，了解其工作原理。

XmlSerializer实例化执行其构造函数的类，并在以后填充其可序列化属性。

要确保正确序列化类的实例，请实现ISerializable接口。您还可以通过实现IXmlSerializable接口来更好地控制XML序列化过程。

Xml在类型中使用Narrowing运算符反序列化属性

1 个答案: