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&lt;T&gt;、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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