Modifier

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ObjectDisposedException Class

Definition

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

Examples

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);
      }
   }
}
open System
open System.IO

let ms = new MemoryStream 16
ms.Close()
try
    ms.ReadByte()
    |> ignore
with :? ObjectDisposedException as e ->
   printfn $"Caught: {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

This code produces the following output:

Caught:
  Cannot access a closed Stream.

Remarks

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

  • You've called an IDisposable object's Dispose method (or an IDisposableAsync object's DisposeAsync 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()
    
    open System
    open System.Threading
    
    let timerNotification _ =
        printfn $"Timer event fired at {DateTime.Now:F}"
    
    let t = new Timer(timerNotification, null, 100, Timeout.Infinite)
    Thread.Sleep 2000
    t.Dispose()
    
    t.Change(200, 1000)
    |> ignore
    Thread.Sleep 3000
    
    // 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 <StartupCode$fs>.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()
    
  • 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. The same is true for CloseAsync and <xref:System.IAsyncDisposable.DisposeAsync%2A?displayProperty=nameWithType>.

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

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.

Constructors

ObjectDisposedException(SerializationInfo, StreamingContext)
Obsolete.

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

ObjectDisposedException(String)

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

ObjectDisposedException(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.

ObjectDisposedException(String, String)

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

Properties

Data

Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Inherited from Exception)
HelpLink

Gets or sets a link to the help file associated with this exception.

(Inherited from Exception)
HResult

Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(Inherited from Exception)
InnerException

Gets the Exception instance that caused the current exception.

(Inherited from Exception)
Message

Gets the message that describes the error.

ObjectName

Gets the name of the disposed object.

Source

Gets or sets the name of the application or the object that causes the error.

(Inherited from Exception)
StackTrace

Gets a string representation of the immediate frames on the call stack.

(Inherited from Exception)
TargetSite

Gets the method that throws the current exception.

(Inherited from Exception)

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetBaseException()

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

(Inherited from Exception)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext)
Obsolete.

Retrieves the SerializationInfo object with the parameter name and additional exception information.

GetObjectData(SerializationInfo, StreamingContext)
Obsolete.

When overridden in a derived class, sets the SerializationInfo with information about the exception.

(Inherited from Exception)
GetType()

Gets the runtime type of the current instance.

(Inherited from Exception)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ThrowIf(Boolean, Object)

Throws an ObjectDisposedException if the specified condition is true.

ThrowIf(Boolean, Type)

Throws an ObjectDisposedException if the specified condition is true.

ToString()

Creates and returns a string representation of the current exception.

(Inherited from Exception)

Events

SerializeObjectState
Obsolete.

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