如何：创建可以由远程对象引发的异常类型

本主题介绍一项传统技术，保留该技术是为了向后兼容现有的应用程序，不建议对新的开发使用该技术。现在应该使用  Windows Communication Foundation (WCF) 来开发分布式应用程序。

通过从 RemotingException 类派生并实现 ISerializable 接口，您可以创建可由远程对象引发并由远程调用方捕获的您自己的异常类型。

创建可由远程对象引发并由远程调用方捕获的异常类型

1. 定义从 RemotingException 类派生的类。

   Public Class RemotableType
      Inherits MarshalByRefObject
         Implements ISerializable
   ' ...
   End Class 'RemotableType
   

   public class RemotableType : MarshalByRefObject{
   // ...
   }
   

2. 为该类定义 SerializableAttribute 特性。

   <Serializable()> Public Class CustomRemotableException
       Inherits RemotingException
       ' ...
   End Class
   

   [Serializable]
   public class CustomRemotableException : RemotingException, ISerializable {
       // ...
   }
   

3. 实现采用 SerializationInfo 对象和 StreamingContext 对象作为参数的反序列化构造函数。

   Public Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext)
           _internalMessage = info.GetValue("_internalMessage", GetType(String))
   End Sub
   

   public CustomRemotableException(SerializationInfo info, StreamingContext context) {
         _internalMessage = (string)info.GetValue("_internalMessage", typeof(string));
    }
   

示例

下面的代码示例提供了一个简单实现，该实现若经过配置，则可在远程服务器对象引发异常时复制回调用方。

<Serializable()> Public Class CustomRemotableException
    Inherits RemotingException
    Implements ISerializable

    Private _internalMessage As String

    Public Sub New()
        _internalMessage = String.Empty
    End Sub

    Public Sub New(ByVal message As String)
        _internalMessage = message
    End Sub

    Public Sub New(ByVal info As SerializationInfo, ByVal context As StreamingContext)
        _internalMessage = info.GetValue("_internalMessage", GetType(String))
    End Sub

    Public Overrides Sub GetObjectData(ByVal info As SerializationInfo, ByVal context As StreamingContext)
        info.AddValue("_internalMessage", _internalMessage)
    End Sub

    Public Overrides ReadOnly Property Message() As String
        Get
            Return "This is your custom remotable exception returning : """ + _internalMessage + """"
        End Get
    End Property
End Class

[Serializable]
public class CustomRemotableException : RemotingException, ISerializable
{
    private string _internalMessage;

    public CustomRemotableException()
    {
        _internalMessage = String.Empty;
    }

    public CustomRemotableException(string message)
    {
        _internalMessage = message;
    }

    public CustomRemotableException(SerializationInfo info, StreamingContext context)
    {
        _internalMessage = (string)info.GetValue("_internalMessage", typeof(string));
    }

    public override void GetObjectData(SerializationInfo info, StreamingContext context)
    {
         info.AddValue("_internalMessage", _internalMessage);
    }

     // Returns the exception information. 
     public override string Message
     {
         get
         {
             return "This is your custom remotable exception returning: \""
          + _internalMessage
          + "\"";
         }
     }
}

另请参见

参考

ContextBoundObject

概念

可远程处理和不可远程处理的对象

生成日期：2010-02-13