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.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.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.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.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
Web.config
3、客户端
Hello.aspx
Hello.aspx.cs
Web.config
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