在ASP.NET中使用SOAP Extensions捕获WebService异常

Application_Error不能捕获的异常

      [WebMethod]
        public string HelloWorld()
        {
            throw new Exception("this exption can't be handled by Application_Error Method");
            return "Hello World";
        }

定义Application_Error将不能捕获这个异常.

原因需要了解一下SOAP请求的在ASP.NET的生命周期.

Process Message过程调用WebMethod时如果产生SoapException,SoapHeaderException 被序列化后,返回在SOAP <Fault>结点.

使用SOAP extension扩展处理Process Message过程产生的异常
我们可以SOAP Extension处理

Code
public class SoapExceptionHandler : System.Web.Services.Protocols.SoapExtension
    {
        public override void ProcessMessage(System.Web.Services.Protocols.SoapMessage message)
        {
            if (message.Stage == SoapMessageStage.AfterSerialize)
            {
                if (message.Exception != null)
                {
                    LogUtil.Log.Error(message.Exception.InnerException);
                }
            }
        }

        public override object GetInitializer(Type serviceType)
        {
            return null;
        }

        public override object GetInitializer(
            LogicalMethodInfo methodInfo,
            SoapExtensionAttribute attribute)
        {
            return null;
        }

        public override void Initialize(object initializer) 
        {
        }
    }

在Web.config system.web结点中配置

Code
        <webServices>
            <soapExtensionTypes>
                <add type="Elplan.App.SoapExceptionHandler, Elplan.App" priority="1" group="High" />
            </soapExtensionTypes>
        </webServices>

调试:

如果使用VS直接运行调试asmx,是不可以的.(因为...它不是一个完整的SOAP请求.)可使用WebServiceStudio.
相关地址:http://www.codeplex.com/WebserviceStudio 

参考文章:

Using SOAP Extensions in ASP.NET
Handling and Throwing Exceptions in XML Web Services
How to create a global exception handler for a Web Service