ObjectDisposedException 类

定义

对已释放的对象执行操作时所引发的异常。The exception that is thrown when an operation is performed on a disposed object.

public ref class ObjectDisposedException : InvalidOperationException
[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public class ObjectDisposedException : InvalidOperationException
type ObjectDisposedException = class
    inherit InvalidOperationException
Public Class ObjectDisposedException
Inherits InvalidOperationException
继承
属性

示例

下面的示例演示导致ObjectDisposedException引发异常的错误。The following example demonstrates an error that causes the ObjectDisposedException exception to be thrown.

using namespace System;
using namespace System::IO;
int main()
{
   MemoryStream^ ms = gcnew MemoryStream( 16 );
   ms->Close();
   try
   {
      ms->ReadByte();
   }
   catch ( ObjectDisposedException^ e ) 
   {
      Console::WriteLine( "Caught: {0}", e->Message );
   }

}

using System;
using System.IO;

public class ObjectDisposedExceptionTest 
{
   public static void Main()
   {     
      MemoryStream ms = new MemoryStream(16);
      ms.Close();
      try 
      {
         ms.ReadByte();
      } 
      catch (ObjectDisposedException e) 
      {
         Console.WriteLine("Caught: {0}", e.Message);
      }
   }
}
Imports System.IO

Public Class ObjectDisposedExceptionTest
   
   Public Shared Sub Main()
      Dim ms As New MemoryStream(16)
      ms.Close()
      Try
         ms.ReadByte()
      Catch e As ObjectDisposedException
         Console.WriteLine("Caught: {0}", e.Message)
      End Try
   End Sub
End Class

此代码生成以下输出:This code produces the following output:

Caught:  
  Cannot access a closed Stream.  

注解

当你尝试访问IDisposable实现接口的对象的成员, 并且该对象已被释放时,将引发。ObjectDisposedExceptionAn ObjectDisposedException is thrown when you try to access a member of an object that implements the IDisposable interface, and that object has been disposed. 通常, 此异常由下列情况之一引起:Typically, this exception is caused by one of the following conditions:

  • 您已经调用了对象的Dispose方法, 并且试图访问获取或设置该对象状态的实例成员。You've called an object's Dispose method, and you're trying to access an instance member that gets or sets the object's state. 下面的示例演示在ObjectDisposedException Timer.Dispose调用方法之后尝试重置计时器通知的频率时引发的。The following example illustrates the ObjectDisposedException that is thrown when you try to reset the frequency of timer notifications after you call the Timer.Dispose method.

    using System;
    using System.Threading;
    
    public class Example
    {
       public static void Main()
       {
          Timer t = new Timer(TimerNotification, null, 
                             100, Timeout.Infinite);
          Thread.Sleep(2000);
          t.Dispose();
          
          t.Change(200, 1000);                   
          Thread.Sleep(3000);
       }
    
       private static void TimerNotification(Object obj)
       {
          Console.WriteLine("Timer event fired at {0:F}", DateTime.Now);
       }
    }
    // The example displays output like the following:
    //    Timer event fired at Monday, July 14, 2014 11:54:08 AM
    //    
    //    Unhandled Exception: System.ObjectDisposedException: Cannot access a disposed object.
    //       at System.Threading.TimerQueueTimer.Change(UInt32 dueTime, UInt32 period)
    //       at Example.Main()
    
    Imports System.Threading
    
    Module Example
       Public Sub Main()
          Dim t As New Timer(AddressOf TimerNotification, Nothing, 
                             100, Timeout.Infinite)
          Thread.Sleep(2000)
          t.Dispose()
          
          t.Change(200, 1000)                   
          Thread.Sleep(3000)
       End Sub
    
       Private Sub TimerNotification(obj As Object)
          Console.WriteLine("Timer event fired at {0:F}", Date.Now)
       End Sub
    End Module
    ' The example displays output like the following:
    '    Timer event fired at Monday, July 14, 2014 11:54:08 AM
    '    
    '    Unhandled Exception: System.ObjectDisposedException: Cannot access a disposed object.
    '       at System.Threading.TimerQueueTimer.Change(UInt32 dueTime, UInt32 period)
    '       at Example.Main()
    
  • 您已经调用了对象的Close方法, 并且试图访问获取或设置该对象状态的实例成员。You've called an object's Close method, and you're trying to access an instance member that gets or sets the object's state. 通常, Close方法提供IDisposable.Dispose方法的类型公共实现。Often, the Close method provides a type's public implementation of the IDisposable.Dispose method.

  • 您多次调用了对象的Dispose方法。You've called an object's Dispose method multiple times. 通常情况下, 这不会引发异常。Typically, this doesn't throw an exception. 但是, 根据类型的实现IDisposable.Dispose方式, 它可能不允许多次Dispose调用。However, depending on how a type implements IDisposable.Dispose, it may not allow multiple calls to Dispose.

在大多数情况下, 此异常是由开发人员错误导致的。In most cases, this exception results from developer error. 应更正此错误, 而不try是在catch块中/处理错误, 这通常是通过呈现对象进行的。Instead of handling the error in a try/catch block, you should correct the error, typically by reinstantiating the object.

构造函数

ObjectDisposedException(SerializationInfo, StreamingContext)

用序列化数据初始化 ObjectDisposedException 类的新实例。Initializes a new instance of the ObjectDisposedException class with serialized data.

ObjectDisposedException(String)

使用包含已释放对象名称的字符串初始化 ObjectDisposedException 类的新实例。Initializes a new instance of the ObjectDisposedException class with a string containing the name of the disposed object.

ObjectDisposedException(String, Exception)

使用指定的错误消息和对作为此异常原因的内部异常的引用来初始化 ObjectDisposedException 类的新实例。Initializes a new instance of the ObjectDisposedException class with a specified error message and a reference to the inner exception that is the cause of this exception.

ObjectDisposedException(String, String)

使用指定的对象名称和消息初始化 ObjectDisposedException 类的新实例。Initializes a new instance of the ObjectDisposedException class with the specified object name and message.

属性

Data

获取提供有关异常的其他用户定义信息的键/值对集合。Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(继承自 Exception)
HelpLink

获取或设置指向与此异常关联的帮助文件链接。Gets or sets a link to the help file associated with this exception.

(继承自 Exception)
HResult

获取或设置 HRESULT(一个分配给特定异常的编码数字值)。Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(继承自 Exception)
InnerException

获取导致当前异常的 Exception 实例。Gets the Exception instance that caused the current exception.

(继承自 Exception)
Message

获取描述错误的消息。Gets the message that describes the error.

ObjectName

获取已释放对象的名称。Gets the name of the disposed object.

Source

获取或设置导致错误的应用程序或对象的名称。Gets or sets the name of the application or the object that causes the error.

(继承自 Exception)
StackTrace

获取调用堆栈上的即时框架字符串表示形式。Gets a string representation of the immediate frames on the call stack.

(继承自 Exception)
TargetSite

获取引发当前异常的方法。Gets the method that throws the current exception.

(继承自 Exception)

方法

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetBaseException()

当在派生类中重写时,返回 Exception,它是一个或多个并发的异常的根源。When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(继承自 Exception)
GetHashCode()

作为默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetObjectData(SerializationInfo, StreamingContext)

使用参数名和附加异常信息检索 SerializationInfo 对象。Retrieves the SerializationInfo object with the parameter name and additional exception information.

GetType()

获取当前实例的运行时类型。Gets the runtime type of the current instance.

(继承自 Exception)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

创建并返回当前异常的字符串表示形式。Creates and returns a string representation of the current exception.

(继承自 Exception)

事件

SerializeObjectState

当异常被序列化用来创建包含有关该异常的徐列出数据的异常状态对象时会出现该问题。Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

(继承自 Exception)

适用于

另请参阅