ThreadStateException Class

The exception that is thrown when a Thread is in an invalid ThreadState for the method call.

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

<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public Class ThreadStateException
	Inherits SystemException
Dim instance As ThreadStateException

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
public class ThreadStateException extends SystemException
public class ThreadStateException extends SystemException

Once a thread is created, it is in at least one of the ThreadState states until it terminates. ThreadStateException is thrown by methods that cannot perform the requested operation due to the current state of a thread. For example, trying to restart an aborted thread by calling Start on a thread that has terminated throws a ThreadStateException.

ThreadStateException uses the HRESULT COR_E_THREADSTATE, which has the value 0x80131520.

For a list of initial property values for an instance of ThreadStateException, see the ThreadStateException constructors.

The following example demonstrates an error that causes the system to throw a ThreadStateException.

Imports System
Imports System.Threading

Public Class ThreadWork
   Public Shared Sub DoWork()
      Console.WriteLine("Working thread...")
   End Sub 'DoWork
End Class 'ThreadWork

Class ThreadStateTest
   Public Shared Sub Main()
      Dim myThreadDelegate As New ThreadStart(AddressOf ThreadWork.DoWork)
      Dim myThread As New Thread(myThreadDelegate)
      Console.WriteLine("In main. Attempting to restart myThread.")
      Catch e As ThreadStateException
         Console.WriteLine("Caught: {0}", e.Message)
      End Try
   End Sub 'Main
End Class 'ThreadStateTest

import System.*;
import System.Threading.*;

public class ThreadWork
    public static void DoWork()
        Console.WriteLine("Working thread...");
    } //DoWork
} //ThreadWork

class ThreadStateTest
    public static void main(String[] args)
        ThreadStart myThreadDelegate = new ThreadStart(ThreadWork.DoWork);
        System.Threading.Thread myThread =
            new System.Threading.Thread(myThreadDelegate);
        Console.WriteLine("In main. Attempting to restart myThread.");
        try {
        catch (ThreadStateException e) {
            Console.WriteLine("Caught: {0}", e.get_Message());
    } //main
} //ThreadStateTest

This code produces the following output:

 In main. Attempting to restart myThread.
     Working thread...
     Caught: Thread is running or terminated. Cannot restart.


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

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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