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ObjectDisposedException Class

 

The exception that is thrown when an operation is performed on a disposed object.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

System.Object
  System.Exception
    System.SystemException
      System.InvalidOperationException
        System.ObjectDisposedException

[SerializableAttribute]
[ComVisibleAttribute(true)]
public class ObjectDisposedException : InvalidOperationException

NameDescription
System_CAPS_protmethodObjectDisposedException(SerializationInfo, StreamingContext)

Initializes a new instance of the ObjectDisposedException class with serialized data.

System_CAPS_pubmethodObjectDisposedException(String)

Initializes a new instance of the ObjectDisposedException class with a string containing the name of the disposed object.

System_CAPS_pubmethodObjectDisposedException(String, Exception)

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.

System_CAPS_pubmethodObjectDisposedException(String, String)

Initializes a new instance of the ObjectDisposedException class with the specified object name and message.

NameDescription
System_CAPS_pubpropertyData

Gets a collection of key/value pairs that provide additional user-defined information about the exception.(Inherited from Exception.)

System_CAPS_pubpropertyHelpLink

Gets or sets a link to the help file associated with this exception.(Inherited from Exception.)

System_CAPS_pubpropertyHResult

Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.(Inherited from Exception.)

System_CAPS_pubpropertyInnerException

Gets the Exception instance that caused the current exception.(Inherited from Exception.)

System_CAPS_pubpropertyMessage

Gets the message that describes the error.(Overrides Exception.Message.)

System_CAPS_pubpropertyObjectName

Gets the name of the disposed object.

System_CAPS_pubpropertySource

Gets or sets the name of the application or the object that causes the error.(Inherited from Exception.)

System_CAPS_pubpropertyStackTrace

Gets a string representation of the immediate frames on the call stack.(Inherited from Exception.)

System_CAPS_pubpropertyTargetSite

Gets the method that throws the current exception.(Inherited from Exception.)

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGetBaseException()

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

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetObjectData(SerializationInfo, StreamingContext)

Retrieves the SerializationInfo object with the parameter name and additional exception information.(Overrides Exception.GetObjectData(SerializationInfo, StreamingContext).)

System_CAPS_pubmethodGetType()

Gets the runtime type of the current instance.(Inherited from Exception.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodToString()

Creates and returns a string representation of the current exception.(Inherited from Exception.)

NameDescription
System_CAPS_proteventSerializeObjectState

Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.(Inherited from Exception.)

An ObjectDisposedException is thrown when you try to access a member of an object that implements the IDisposable interface, and that object has been disposed. Typically, this exception is caused by one of the following conditions:

  • 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. 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()
    
  • 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. Often, the Close method provides a type's public implementation of the IDisposable.Dispose method.

  • You've called an object's Dispose method multiple times. Typically, this doesn’t throw an exception. However, depending on how a type implements IDisposable.Dispose, it may not allow multiple calls to Dispose.

In most cases, this exception results from developer error. Instead of handling the error in a try/catch block, you should correct the error, typically by reinstantiating the object.

The following example demonstrates an error that causes the ObjectDisposedException exception to be thrown.

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);
      }
   }
}

This code produces the following output:

Caught:
  Cannot access a closed Stream.

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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