c# - IErrorHandler WCF配置为返回文本/纯文本

Question

我正在尝试在wcf服务中强加自定义错误处理程序fo rest endpoin以在错误时返回未包装的字符串

        public void ProvideFault(Exception error,
        MessageVersion version,
        ref Message fault)
    {
         fault = CreateError(error.Message);
         SetContentType();
    }

    private static void SetContentType()
    {
        if (WebOperationContext.Current != null)
        {
            var response = WebOperationContext.Current.OutgoingResponse;
            response.ContentType = "text/plain";
        }
    }

    private static Message CreateError(string message)
    {
        var fault = Message.CreateMessage(MessageVersion.None, "", message);
        return fault;
    }

此代码导致响应头为“文本/纯文本”，但错误消息仍被序列化为xml

<string xmlns="http://schemas.microsoft.com/2003/10/Serialization/">Bad Request</string>

当我将原始格式添加到创建的消息时

private static Message CreateError(string message)
        {
            var fault = Message.CreateMessage(MessageVersion.None, "", message);
            fault.Properties.Add(WebBodyFormatMessageProperty.Name, new WebBodyFormatMessageProperty(WebContentFormat.Raw));
            return fault;
        }

服务停止返回。从WCF返回未包装的字符串错误的方法是什么？从ystem.ServiceModel.Channels，m.b派生有一个内部StringMessage类。我可以以某种方式实例化它？

Answer 1

尝试使用本文介绍的方法:

https://www.codeproject.com/Articles/34632/How-to-Pass-Arbitrary-Data-in-a-Message-Object-usi

private static Message CreateError(string message)
{
    var fault = Message.CreateMessage(MessageVersion.None, "", new TextBodyWriter(message));
    fault.Properties.Add(WebBodyFormatMessageProperty.Name, new WebBodyFormatMessageProperty(WebContentFormat.Raw));
    return fault;
}

// source: https://www.codeproject.com/Articles/34632/How-to-Pass-Arbitrary-Data-in-a-Message-Object-usi
public class TextBodyWriter : BodyWriter
{
    byte[] messageBytes;

    public TextBodyWriter(string message)
        : base(true)
    {
        this.messageBytes = Encoding.UTF8.GetBytes(message);
    }

    protected override void OnWriteBodyContents(XmlDictionaryWriter writer)
    {
        writer.WriteStartElement("Binary");
        writer.WriteBase64(this.messageBytes, 0, this.messageBytes.Length);
        writer.WriteEndElement();
    }
}