System.NotSupportedException：流不支持读取

Question

我有这段代码，它从数据库获取肥皂信封（varchar（max））并从中创建一个XmlDictionaryReader，目标是创建Message（System.ServiceModel.Channels.Message）。

这是代码

public static Stream GenerateStreamFromString(string s)
{           
    var stream = new MemoryStream(Encoding.UTF8.GetBytes(s));               
    return stream;          
}

public static XmlDictionaryReader GenerateXmlDictionaryReader(string s, XmlDictionaryReaderQuotas quota)
{           
    using (var stream = GenerateStreamFromString(s))
    {
        return XmlDictionaryReader.CreateTextReader(stream, quota);
    }           
}

我在这里调用上面的方法

var reader = GenerateXmlDictionaryReader(soapenv, XmlDictionaryReaderQuotas.Max);                       
message = Message.CreateMessage(reader, int.MaxValue, MessageVersion.Soap11);

我收到此错误

System.NotSupportedException: Stream does not support reading.
   at System.IO.__Error.ReadNotSupported()
   at System.IO.BufferedStream.Read(Byte[] array, Int32 offset, Int32 count)
   at System.Xml.EncodingStreamWrapper.Read(Byte[] buffer, Int32 offset, Int32 count)
   at System.Xml.XmlBufferReader.TryEnsureBytes(Int32 count)
   at System.Xml.XmlUTF8TextReader.BufferElement()
   at System.Xml.XmlUTF8TextReader.ReadStartElement()
   at System.Xml.XmlUTF8TextReader.Read()
   at System.Xml.XmlBaseReader.MoveToContent()
   at System.ServiceModel.Channels.StreamedMessage..ctor(XmlDictionaryReader reader, Int32 maxSizeOfHeaders, MessageVersion desiredVersion)
   at System.ServiceModel.Channels.Message.CreateMessage(XmlDictionaryReader envelopeReader, Int32 maxSizeOfHeaders, MessageVersion version)

我还验证了soapenv不为空并且代码中的xml是有效的。我不知道如何解决这个问题。请帮忙。

Answer 1

    using (var stream = GenerateStreamFromString(s))
    {
        return XmlDictionaryReader.CreateTextReader(stream, quota);
    }

当您退出

using

中的方法时，此

return

会处置（/关闭）流 - 您的读者位于死流之上；这就是它不起作用的原因。删除

using

。