化零为整WCF(4) - 异常处理(Exception、FaultException、FaultException、IErrorHandler)

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化零为整WCF(4) - 异常处理(Exception、FaultException、FaultException<T>、IErrorHandler)

作者：webabcd


介绍
WCF(Windows Communication Foundation) - 异常处理：一般Exception的处理，FaultException和FaultException<T>的抛出和处理，使用IErrorHandler处理异常。


示例
1、服务
IHello.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;

namespace WCF.ServiceLib.Exception
{
         /// <summary>
         /// IHello接口
         /// </summary>
        [ServiceContract]
         public interface IHello
        {
                 /// <summary>
                 /// 抛出Exception异常
                 /// </summary>
                [OperationContract]
                 void HelloException();

                 /// <summary>
                 /// 抛出FaultException异常
                 /// </summary>
                [OperationContract]
                 void HelloFaultException();

                 /// <summary>
                 /// 抛出FaultException<T>异常
                 /// </summary>
                [OperationContract]
                [FaultContract( typeof(FaultMessage))]
                 void HelloFaultExceptionGeneric();

                 /// <summary>
                 /// IErrorHandler处理异常
                 /// </summary>
                [OperationContract]
                 void HelloIErrorHandler();
        }
}

 

FaultMessage.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
using System.Runtime.Serialization;

namespace WCF.ServiceLib.Exception
{
         /// <summary>
         /// 错误信息实体类（用于错误契约FaultContract）
         /// </summary>
        [DataContract]
         public class FaultMessage
        {
                 /// <summary>
                 /// 错误信息
                 /// </summary>
                [DataMember]
                 public string Message { get; set; }

                 /// <summary>
                 /// 错误代码
                 /// </summary>
                [DataMember]
                 public int ErrorCode { get; set; }
        }
}

 

FaultErrorHandler.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel.Dispatcher;
using System.Configuration;
using System.ServiceModel;
using System.ServiceModel.Channels;

namespace WCF.ServiceLib.Exception
{
         /// <summary>
         /// 自定义错误处理器（继承自System.ServiceModel.Dispatcher.IErrorHandler）
         /// </summary>
         public class FaultErrorHandler : IErrorHandler
        {
                 /// <summary>
                 /// 在异常返回给客户端之后被调用
                 /// </summary>
                 /// <param name="error">异常</param>
                 /// <returns></returns>
                 public bool HandleError(System.Exception error)
                {
                        System.IO.StreamWriter sw = new System.IO.StreamWriter( @"C:\WCF_Log.txt", true);
                        sw.Write( "IErrorHandler - HandleError测试。错误类型：{0}；错误信息：{1}", error.GetType().ToString(), error.Message);
                        sw.WriteLine();
                        sw.Flush();
                        sw.Close();

                         // true - 已处理
                         return true;
                }

                 /// <summary>
                 /// 在异常发生后，异常信息返回前被调用
                 /// </summary>
                 /// <param name="error">异常</param>
                 /// <param name="version">SOAP版本</param>
                 /// <param name="fault">返回给客户端的错误信息</param>
                 public void ProvideFault(System.Exception error, System.ServiceModel.Channels.MessageVersion version, ref System.ServiceModel.Channels.Message fault)
                {
                         if (error is System.IO.IOException)
                        {
                                FaultException ex = new FaultException( "IErrorHandler - ProvideFault测试");

                                MessageFault mf = ex.CreateMessageFault();

                                fault = Message.CreateMessage(version, mf, ex.Action);

                                 // InvalidOperationException error = new InvalidOperationException("An invalid operation has occurred.");
                                 // MessageFault mfault = MessageFault.CreateFault(new FaultCode("Server", new FaultCode(String.Format("Server.{0}", error.GetType().Name))), new FaultReason(error.Message), error);
                                 // FaultException fe = FaultException.CreateFault(mfault, typeof(InvalidOperationException));
                        }
                }
        }
}

 

Hello.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;

namespace WCF.ServiceLib.Exception
{
         /// <summary>
         /// Hello类
         /// </summary>
         public class Hello : IHello, IDisposable, IServiceBehavior    
        {
                 /// <summary>
                 /// 抛出Exception异常
                 /// </summary>
                 public void HelloException()
                {
                         throw new System.Exception( "抛出Exception异常");
                }

                 /// <summary>
                 /// 抛出FaultException异常
                 /// </summary>
                 public void HelloFaultException()
                {
                         throw new FaultException( "抛出FaultException异常", new FaultCode( "服务"));
                }

                 /// <summary>
                 /// 抛出FaultException<T>异常
                 /// </summary>
                 public void HelloFaultExceptionGeneric()
                {
                         throw new FaultException<FaultMessage>( new FaultMessage { Message = "抛出FaultException<T>异常", ErrorCode = -1 }, "为了测试FaultException<T>用的");
                }

                 /// <summary>
                 /// IErrorHandler处理异常
                 /// </summary>
                 public void HelloIErrorHandler()
                {
                         throw new System.IO.IOException( "抛出异常，用IErrorHandler处理");
                }

                 /// <summary>
                 /// 实现IDisposable接口的Dispose()方法
                 /// </summary>
                 public void Dispose()
                {

                }

                 /// <summary>
                 /// 为契约增加自定义绑定参数
                 /// </summary>
                 /// <param name="serviceDescription">服务描述</param>
                 /// <param name="serviceHostBase">服务宿主</param>
                 /// <param name="endpoints">服务端点</param>
                 /// <param name="bindingParameters">需要增加的自定义绑定参数</param>
                 public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, System.Collections.ObjectModel.Collection<ServiceEndpoint> endpoints, System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
                {

                }

                 /// <summary>
                 /// runtime时修改属性值或增加自定义扩展对象
                 /// </summary>
                 /// <param name="serviceDescription">服务描述</param>
                 /// <param name="serviceHostBase">服务宿主</param>
                 public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
                {
                        IErrorHandler handler = new FaultErrorHandler();

                         foreach (ChannelDispatcher dispatcher in serviceHostBase.ChannelDispatchers)
                        {
                                 // 增加错误处理器
                                dispatcher.ErrorHandlers.Add(handler);
                        }
                }

                 /// <summary>
                 /// 检查服务描述和服务宿主，以确认服务可以成功运行
                 /// </summary>
                 /// <param name="serviceDescription">服务描述</param>
                 /// <param name="serviceHostBase">服务宿主</param>
                 public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
                {

                }
        }
}

 

 

2、宿主
Hello.svc

<%@ ServiceHost Language="C#" Debug="true" Service="WCF.ServiceLib.Exception.Hello" %>

 

Web.config

<?xml version="1.0"?>
<configuration>
    <system.serviceModel>
        <behaviors>
            <serviceBehaviors>
                <behavior name="ExceptionBehavior">
                    <!--httpGetEnabled - 使用get方式提供服务-->
                    <serviceMetadata httpGetEnabled="true" />
                    <serviceDebug includeExceptionDetailInFaults="true"/>
                </behavior>
            </serviceBehaviors>
        </behaviors>
        <services>
            <!--name - 提供服务的类名-->
            <!--behaviorConfiguration - 指定相关的行为配置-->
            <service name="WCF.ServiceLib.Exception.Hello" behaviorConfiguration="ExceptionBehavior">
                <!--address - 服务地址-->
                <!--binding - 通信方式-->
                <!--contract - 服务契约-->
                <endpoint address="" binding="wsHttpBinding" contract="WCF.ServiceLib.Exception.IHello" />
            </service>
        </services>
    </system.serviceModel>
</configuration>

 

 

3、客户端
Hello.aspx

<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Hello.aspx.cs"
        Inherits="Exception_Hello" Title="异常处理(Exception、FaultException、FaultException<T>、IErrorHandler)" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
        <div>
                <asp:Label ID="lblMsg" runat="server" />
        </div>
        <br />
        <div>
                <asp:Button ID="btnHelloException" runat="server" Text="HelloException" OnClick="btnHelloException_Click" />
        </div>
        <div>
                <asp:Button ID="btnHelloFaultException" runat="server" Text="HelloFaultException"
                        OnClick="btnHelloFaultException_Click" />
        </div>
        <div>
                <asp:Button ID="btnHelloFaultExceptionGeneric" runat="server" Text="HelloFaultExceptionGeneric"
                        OnClick="btnHelloFaultExceptionGeneric_Click" />
        </div>
        <div>
                <asp:Button ID="btnHelloIErrorHandler" runat="server" Text="HelloIErrorHandler" OnClick="btnHelloIErrorHandler_Click" />
        </div>
</asp:Content>

 

Hello.aspx.cs

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

using System.ServiceModel;

public partial class Exception_Hello : System.Web.UI.Page
{
         protected void Page_Load( object sender, EventArgs e)
        {

        }

         protected void btnHelloException_Click( object sender, EventArgs e)
        {
                ExceptionService.HelloClient proxy = new ExceptionService.HelloClient();
                 try
                {
                        proxy.HelloException();
                }
                 catch (Exception ex)
                {
                        lblMsg.Text = ex.Message;
                }
                 finally
                {
                         try
                        {
                                proxy.Close();
                        }
                         catch (Exception ex)
                        {
                                lblMsg.Text += "<br />" + ex.Message;
                        }
                }
        }

         protected void btnHelloFaultException_Click( object sender, EventArgs e)
        {
                ExceptionService.HelloClient proxy = new ExceptionService.HelloClient();
                 try
                {
                        proxy.HelloFaultException();
                }
                 catch (FaultException ex)
                {
                        lblMsg.Text = string.Format( "错误编码：{0}；错误原因：{1}",
                                ex.Code.Name,
                                ex.Reason.ToString());
                }
                 finally
                {
                        proxy.Close();
                }
        }

         protected void btnHelloFaultExceptionGeneric_Click( object sender, EventArgs e)
        {
                ExceptionService.HelloClient proxy = new ExceptionService.HelloClient();
                 try
                {
                        proxy.HelloFaultExceptionGeneric();
                }
                 catch (System.ServiceModel.FaultException<ExceptionService.FaultMessage> ex)
                {
                        lblMsg.Text = string.Format( "错误代码：{0}；错误信息：{1}；错误原因：{2}",
                                ex.Detail.ErrorCode.ToString(),
                                ex.Detail.Message,
                                ex.Reason.ToString());
                }
                 finally
                {
                        proxy.Close();
                }
        }

         protected void btnHelloIErrorHandler_Click( object sender, EventArgs e)
        {
                ExceptionService.HelloClient proxy = new ExceptionService.HelloClient();
                 try
                {
                        proxy.HelloIErrorHandler();
                }
                 catch (Exception ex)
                {
                        System.ServiceModel.FaultException faultException = ex as System.ServiceModel.FaultException;

                         if (faultException != null)
                        {
                                lblMsg.Text = string.Format( "错误信息：{0}", faultException.Message);
                        }
                         else
                        {
                                lblMsg.Text = ex.ToString();
                        }
                }
                 finally
                {
                        proxy.Close();
                }
        }
}

 

Web.config

<?xml version="1.0"?>
<configuration>
    <system.serviceModel>
        <client>
            <!--address - 服务地址-->
            <!--binding - 通信方式-->
            <!--contract - 服务契约-->
            <endpoint address="http://localhost:3502/ServiceHost/Exception/Hello.svc" binding="wsHttpBinding" contract="ExceptionService.IHello" />
        </client>
    </system.serviceModel>
</configuration>

 

 

运行结果：
单击" btnHelloException"后显示
抛出Exception异常
The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state.  

单击" btnHelloFaultException"后显示
错误编码：服务；错误原因：抛出FaultException异常

单击" btnHelloFaultExceptionGeneric"后显示
错误代码：-1；错误信息：抛出FaultException异常；错误原因：为了测试FaultException用的

单击" btnHelloIErrorHandler"后显示
错误信息：IErrorHandler - ProvideFault测试


OK
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