ObjectDisposedException Class

Definition

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

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

Examples

下面的示例演示导致引发 ObjectDisposedException 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.  

Remarks

当你尝试访问实现 IDisposable 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,而您试图访问的实例成员正在获取或设置该对象的状态。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. 下面的示例演示在调用 Timer.Dispose 方法后,当你尝试重置计时器通知的频率时引发的 ObjectDisposedExceptionThe 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,而您试图访问的实例成员正在获取或设置该对象的状态。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 方法提供类型的 IDisposable.Dispose 方法的公共实现。Often, the Close method provides a type's public implementation of the IDisposable.Dispose method.

  • 你多次调用了对象的 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,根据类型实现 IDisposable.Dispose的方式,它可能不允许多次调用 DisposeHowever, 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,而不是处理 try/catch 块中的错误,通常是呈现对象。Instead of handling the error in a try/catch block, you should correct the error, typically by reinstantiating the object.

Constructors

ObjectDisposedException(SerializationInfo, StreamingContext)

使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.

Properties

Data

获取键/值对的集合,这些键/值对提供有关该异常的其他用户定义信息。Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Inherited from 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.

(Inherited from 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.

(Inherited from Exception)
InnerException

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

(Inherited from 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.

(Inherited from 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.

(Inherited from Exception)
TargetSite

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

(Inherited from Exception)

Methods

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.

(Inherited from 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本原因。When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(Inherited from Exception)
GetHashCode()

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

(Inherited from 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.

GetObjectData(SerializationInfo, StreamingContext)

当在派生类中重写时,用关于异常的信息设置 SerializationInfoWhen overridden in a derived class, sets the SerializationInfo with information about the exception.

(Inherited from Exception)
GetType()

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

(Inherited from Exception)
MemberwiseClone()

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

(Inherited from 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.

(Inherited from Exception)

Events

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.

(Inherited from Exception)

Applies to

See also