.net 从SOAP请求反序列化XML时出现问题

我很难将XML从SOAP请求反序列化到对象

XML如下所示（我可以控制它，因此可以更改）：

但我一直得到以下错误：

There is an error in XML document (1, 2).
<OrderRequest xmlns='http://service.test.com/ServiceMessages/v001'> was not expected.

XML文档（1，2）中存在错误。
没有预料到。

我尝试过剥离名称空间、前缀，省略XmlSerializer的XmlRootAttribute参数。。。导致不同的错误消息或空对象。。。

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我有什么遗漏或做错了吗？我已经盯着它看了将近两天了，我担心我忽略了什么。

为XmlSerializer的XmlRootAttribute提供名称空间完成了这项工作：

Dim xmlSerializer = New XmlSerializer( _
    GetType(Service.OrderRequest), _
    New XmlRootAttribute("OrderRequest") _
        With {.Namespace = "http://service.test.com/ServiceMessages/v001"})

...

Dim xmlString = requestEnvelope.Body.InnerXml
Dim orderRequest As Service.OrderRequest = Nothing

Using xmlTextReader = New XmlTextReader(New MemoryStream(xmlString))
    Dim xmlSerializer = New XmlSerializer(GetType(Service.OrderRequest), New XmlRootAttribute("OrderRequest"))

    orderRequest = CType(xmlSerializer.Deserialize(xmlTextReader), Service.OrderRequest)
End Using

...

There is an error in XML document (1, 2).
<OrderRequest xmlns='http://service.test.com/ServiceMessages/v001'> was not expected.

Dim xmlSerializer = New XmlSerializer( _
    GetType(Service.OrderRequest), _
    New XmlRootAttribute("OrderRequest") _
        With {.Namespace = "http://service.test.com/ServiceMessages/v001"})