Exception.SerializeObjectState Exception.SerializeObjectState Exception.SerializeObjectState Exception.SerializeObjectState Event

定義

當例外狀況序列化,以建立包含例外狀況相關序列化資料的例外狀況狀態物件時,就會發生此事件。Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

protected:
 event EventHandler<System::Runtime::Serialization::SafeSerializationEventArgs ^> ^ SerializeObjectState;
protected event EventHandler<System.Runtime.Serialization.SafeSerializationEventArgs> SerializeObjectState;
member this.SerializeObjectState : EventHandler<System.Runtime.Serialization.SafeSerializationEventArgs> 
Protected Custom Event SerializeObjectState As EventHandler(Of SafeSerializationEventArgs) 

範例

下列範例會定義BadDivisionException處理SerializeObjectState事件。The following example defines a BadDivisionException that handles the SerializeObjectState event. 它也包含狀態的物件,也就是巢狀結構,名為BadDivisionExceptionState實作ISafeSerializationData介面。It also contains a state object, which is a nested structure named BadDivisionExceptionState that implements the ISafeSerializationData interface.

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

public class Example
{
   public static void Main()
   {
      bool serialized = false;
      var formatter = new BinaryFormatter();
      Double[] values = { 3, 2, 1 };
      Double divisor = 0;
      foreach (var value in values) {
         try {
            BadDivisionException ex = null;
            if (divisor == 0) { 
               if (! serialized) {
                  // Instantiate the exception object.
                  ex = new BadDivisionException(0);
                  // Serialize the exception object.
                  var fs = new FileStream("BadDivision1.dat", 
                                           FileMode.Create);
                  formatter.Serialize(fs, ex);
                  fs.Close();
                  Console.WriteLine("Serialized the exception...");
               }
               else {
                  // Deserialize the exception.
                  var fs = new FileStream("BadDivision1.dat",
                                           FileMode.Open);
                  ex = (BadDivisionException) formatter.Deserialize(fs);
                  // Reserialize the exception.
                  fs.Position = 0;
                  formatter.Serialize(fs, ex);
                  fs.Close();
                  Console.WriteLine("Reserialized the exception...");                                            
               }   
              throw ex; 
            } 
            Console.WriteLine("{0} / {1} = {1}", value, divisor, value/divisor);
         }   
         catch (BadDivisionException e) {
            Console.WriteLine("Bad divisor from a {0} exception: {1}",
                              serialized ? "deserialized" : "new", e.Divisor);             
            serialized = true;
         }   
      }
   }
}

[Serializable] public class BadDivisionException : Exception
{
   // Maintain an internal BadDivisionException state object.
   [NonSerialized] private BadDivisionExceptionState state = new BadDivisionExceptionState();

   public BadDivisionException(Double divisor)
   {
      state.Divisor = divisor;
      HandleSerialization();      
   }
   
   private void HandleSerialization()
   {
      SerializeObjectState += delegate(object exception, SafeSerializationEventArgs eventArgs) 
                                      { 
                                          eventArgs.AddSerializedState(state);
                                      };
   }
   
   public Double Divisor
   { get { return state.Divisor; } }

   [Serializable] private struct BadDivisionExceptionState : ISafeSerializationData 
   {
      private Double badDivisor;
      
      public Double Divisor
      { get { return badDivisor; } 
        set { badDivisor = value; } }

      void ISafeSerializationData.CompleteDeserialization(object deserialized)
      { 
         var ex = deserialized as BadDivisionException;
         ex.HandleSerialization();
         ex.state = this; 
      }
   }
}
// The example displays the following output:
//       Serialized the exception...
//       Bad divisor from a new exception: 0
//       Reserialized the exception...
//       Bad divisor from a deserialized exception: 0
//       Reserialized the exception...
//       Bad divisor from a deserialized exception: 0
Imports System.IO
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Binary
           
Module Example
   Public Sub Main()
      Dim serialized As Boolean = False
      Dim formatter As New BinaryFormatter()
      Dim values() As Double = { 3, 2, 1 }
      Dim divisor As Double = 0
      For Each value In values
         Try
            Dim ex As BadDivisionException = Nothing
            If divisor = 0 Then 
               If Not serialized Then
                  ' Instantiate the exception object.
                  ex = New BadDivisionException(0)
                  ' Serialize the exception object.
                  Dim fs As New FileStream("BadDivision1.dat", 
                                           FileMode.Create)
                  formatter.Serialize(fs, ex)
                  fs.Close()
                  Console.WriteLine("Serialized the exception...")
               Else
                  ' Deserialize the exception.
                  Dim fs As New FileStream("BadDivision1.dat",
                                           FileMode.Open)
                  ex = CType(formatter.Deserialize(fs), BadDivisionException)
                  ' Reserialize the exception.
                  fs.Position = 0
                  formatter.Serialize(fs, ex)
                  fs.Close()
                  Console.WriteLine("Reserialized the exception...")                                            
               End If   
              Throw ex 
            End If 
            Console.WriteLine("{0} / {1} = {1}", value, divisor, value/divisor)
         Catch e As BadDivisionException
            Console.WriteLine("Bad divisor from a {0} exception: {1}",
                              If(serialized, "deserialized", "new"), e.Divisor)             
            serialized = True
         End Try   
      Next
   End Sub
End Module

<Serializable> Public Class BadDivisionException : Inherits Exception
   ' Maintain an internal BadDivisionException state object.
   <NonSerialized> Private state As New BadDivisionExceptionState()

   Public Sub New(divisor As Double)
      state.Divisor = divisor
      HandleSerialization()      
   End Sub
   
   Private Sub HandleSerialization()
      AddHandler SerializeObjectState, 
                 Sub(exception As Object, eventArgs As SafeSerializationEventArgs)
                    eventArgs.AddSerializedState(state)
                 End Sub
   End Sub
   
   Public ReadOnly Property Divisor As Double
      Get
         Return state.Divisor
      End Get      
   End Property

   <Serializable> Private Structure BadDivisionExceptionState 
                                    Implements ISafeSerializationData
      private badDivisor As Double
      
      Public Property Divisor As Double
         Get
            Return badDivisor
         End Get
         Set
            badDivisor = value
         End Set
      End Property 

      Sub CompleteDeserialization(deserialized As Object) _
            Implements ISafeSerializationData.CompleteDeserialization
         Dim ex As BadDivisionException = TryCast(deserialized, BadDivisionException)
         ex.HandleSerialization()
         ex.state = Me 
      End Sub
   End Structure
End Class
' The example displays the following output:
'       Serialized the exception...
'       Bad divisor from a new exception: 0
'       Reserialized the exception...
'       Bad divisor from a deserialized exception: 0
'       Reserialized the exception...
'       Bad divisor from a deserialized exception: 0

BadDivisionException浮點的除數為零,就會發生時擲回例外狀況。The BadDivisionException exception is thrown when a floating-point division by zero occurs. 第一個除數為零,在此範例會具現化BadDivisionException物件序列化,並擲回例外狀況。During the first division by zero, the example instantiates a BadDivisionException object, serializes it, and throws the exception. 為零的後續部門發生時,此範例會將先前序列化的物件還原序列化、 這,並擲回例外狀況。When subsequent divisions by zero occur, the example deserializes the previously serialized object, reserializes it, and throws the exception. 若要提供物件序列化、 還原序列化、 雷同和還原序列化,此範例會新增SerializeObjectState事件處理常式這兩個BadDivisionException類別建構函式和ISafeSerializationData.CompleteDeserialization實作。To provide for object serialization, deserialization, reserialization, and deserialization, the example adds the SerializeObjectState event handler both in the BadDivisionException class constructor and in the ISafeSerializationData.CompleteDeserialization implementation.

備註

例外狀況狀態物件會實作ISafeSerializationData介面。The exception state object implements the ISafeSerializationData interface.

SerializeObjectState訂閱事件、 例外狀況是還原序列化,並建立成空的例外狀況。When the SerializeObjectState event is subscribed to, the exception is deserialized and created as an empty exception. 例外狀況的建構函式時不執行,並也會還原序列化的例外狀況狀態。The exception's constructor is not run, and the exception state is also deserialized. CompleteDeserialization回呼方法的例外狀況的狀態物件再收到通知,讓它可以將已還原序列化的資料推送至空的例外狀況。The CompleteDeserialization callback method of the exception state object is then notified so that it can push deserialized data into the empty exception.

SerializeObjectState事件可讓透明的例外狀況型別序列化和還原序列化例外狀況資料。The SerializeObjectState event enables transparent exception types to serialize and deserialize exception data. 透明程式碼可以執行它正在運作中的權限集合的範圍內的命令,但無法執行、 呼叫、 衍生自或包含關鍵程式碼。Transparent code can execute commands within the bounds of the permission set it is operating within, but cannot execute, call, derive from, or contain critical code.

如果SerializeObjectState事件沒有訂閱,還原序列化發生如往常般使用Exception建構函式。If the SerializeObjectState event is not subscribed to, deserialization occurs as usual using the Exception constructor.

一般而言,處理常式SerializeObjectState提供其序列化的例外狀況的建構函式中加入事件。Typically, a handler for the SerializeObjectState event is added in the exception's constructor to provide for its serialization. 但因為建構函式不是執行的時機SerializeObjectState事件處理常式執行時,序列化的已還原序列化的例外狀況可能會擲回SerializationException當您嘗試還原序列化例外狀況的例外狀況。But because the constructor is not executed when the SerializeObjectState event handler executes, serializing a deserialized exception can throw a SerializationException exception when you try to deserialize the exception. 若要避免這個問題,您還應該加入的處理常式SerializeObjectState中的事件ISafeSerializationData.CompleteDeserialization方法。To avoid this, you should also add the handler for the SerializeObjectState event in the ISafeSerializationData.CompleteDeserialization method. 請參閱圖範例 > 一節。See the Examples section for an illustration.

給繼承者的注意事項

如果此事件是訂閱,並使用,請依照下列繼承階層架構中的所有衍生型別必須實作相同的序列化機制。If this event is subscribed to and used, all derived types that follow in the inheritance hierarchy must implement the same serialization mechanism.

適用於