WCF IClientMessageInspector.BeforeSendRequest 修改请求

Question

我正在尝试修改 WCF 服务中的请求。

public object BeforeSendRequest(ref Message request, IClientChannel channel)
{
    string xmlRequest = request.ToString();

    XDocument xDoc = XDocument.Parse(xmlRequest);

    //Some request modifications
    //Here i have XML what in want to send

    request = Message.CreateMessage(request.Version, request.Headers.Action, WhatHere?);
    request.Headers.Clear();            

    return null;
}

但我不知道我可以设置什么，CreateMessage或者可能是将我的 XML 设置为请求的不同方式。

Answer 1

您可以传递一个表示修改后的消息的XmlReader对象。下面是从文章如何通过自定义 MessageInspector 检查和修改 WCF 消息中获取的示例。

public object BeforeSendRequest(ref System.ServiceModel.Channels.Message request, System.ServiceModel.IClientChannel channel)
{
    Console.WriteLine("====SimpleMessageInspector+BeforeSendRequest is called=====");

    //modify the request send from client(only customize message body)
    request = TransformMessage2(request);

    return null;
}

//only read and modify the Message Body part
private Message TransformMessage2(Message oldMessage)
{
    Message newMessage = null;

    //load the old message into XML
    MessageBuffer msgbuf = oldMessage.CreateBufferedCopy(int.MaxValue);

    Message tmpMessage = msgbuf.CreateMessage();
    XmlDictionaryReader xdr = tmpMessage.GetReaderAtBodyContents();

    XmlDocument xdoc = new XmlDocument();
    xdoc.Load(xdr);
    xdr.Close();

    //transform the xmldocument
    XmlNamespaceManager nsmgr = new XmlNamespaceManager(xdoc.NameTable);
    nsmgr.AddNamespace("a", "urn:test:datacontracts");

    XmlNode node = xdoc.SelectSingleNode("//a:StringValue", nsmgr);
    if(node!= null) node.InnerText = "[Modified in SimpleMessageInspector]" + node.InnerText;

    MemoryStream ms = new MemoryStream();
    XmlWriter xw = XmlWriter.Create(ms);
    xdoc.Save(xw);
    xw.Flush();
    xw.Close();

    ms.Position = 0;
    XmlReader xr = XmlReader.Create(ms);

    //create new message from modified XML document
    newMessage = Message.CreateMessage(oldMessage.Version, null,xr );
    newMessage.Headers.CopyHeadersFrom(oldMessage);
    newMessage.Properties.CopyProperties(oldMessage.Properties);

    return newMessage;
}