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Thread.ThreadState Property

Gets a value containing the states of the current thread.

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

public ThreadState ThreadState { get; }

Property Value

Type: System.Threading.ThreadState
One of the ThreadState values indicating the state of the current thread. The initial value is Unstarted.

The ThreadState property provides more specific information than the IsAlive property.

Important noteImportant

Thread state is only of interest in debugging scenarios. Your code should never use thread state to synchronize the activities of threads.

The following code example demonstrates accessing the ThreadState of a thread.


using System;
using System.Threading;

class ApartmentTest
{
    static void Main()
    {
        Thread newThread = 
            new Thread(new ThreadStart(ThreadMethod));
        newThread.SetApartmentState(ApartmentState.MTA);

        // The following line is ignored since 
        // ApartmentState can only be set once.
        newThread.SetApartmentState(ApartmentState.STA);

        Console.WriteLine("ThreadState: {0}, ApartmentState: {1}", 
            newThread.ThreadState, newThread.ApartmentState);

        newThread.Start();

        // Wait for newThread to start and go to sleep.
        Thread.Sleep(300);
        try
        {
            // This causes an exception since newThread is sleeping.
            newThread.SetApartmentState(ApartmentState.STA);
        }
        catch(ThreadStateException stateException)
        {
            Console.WriteLine("\n{0} caught:\n" +
                "Thread is not in the Unstarted or Running state.", 
                stateException.GetType().Name);
            Console.WriteLine("ThreadState: {0}, ApartmentState: {1}",
                newThread.ThreadState, newThread.GetApartmentState());
        }
    }

    static void ThreadMethod()
    {
        Thread.Sleep(1000);
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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