Export (0) Print
Expand All

WaitHandle.WaitOne Method (Int32)

Blocks the current thread until the current WaitHandle receives a signal, using a 32-bit signed integer to specify the time interval.

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

public virtual bool WaitOne(
	int millisecondsTimeout
)

Parameters

millisecondsTimeout
Type: System.Int32

The number of milliseconds to wait, or Timeout.Infinite (-1) to wait indefinitely.

Return Value

Type: System.Boolean
true if the current instance receives a signal; otherwise, false.

ExceptionCondition
ObjectDisposedException

The current instance has already been disposed.

ArgumentOutOfRangeException

millisecondsTimeout is a negative number other than -1, which represents an infinite time-out.

AbandonedMutexException

The wait completed because a thread exited without releasing a mutex. This exception is not thrown on Windows 98 or Windows Millennium Edition.

InvalidOperationException

The current instance is a transparent proxy for a WaitHandle in another application domain.

If millisecondsTimeout is zero, the method does not block. It tests the state of the wait handle and returns immediately.

The caller of this method blocks until the current instance receives a signal or a time-out occurs. Use this method to block until a WaitHandle receives a signal from another thread, such as is generated when an asynchronous operation completes. For more information, see the IAsyncResult interface.

Override this method to customize the behavior of derived classes.

Calling this method overload is the same as calling the WaitOne(Int32, Boolean) overload and specifying false for exitContext.

The following code example shows how to use a wait handle to keep a process from terminating while it waits for a background thread to finish executing.

using System;
using System.Threading;

class WaitOne
{
    static AutoResetEvent autoEvent = new AutoResetEvent(false);

    static void Main()
    {
        Console.WriteLine("Main starting.");

        ThreadPool.QueueUserWorkItem(
            new WaitCallback(WorkMethod), autoEvent);

        // Wait for work method to signal. 
        if(autoEvent.WaitOne(1000))
        {
            Console.WriteLine("Work method signaled.");
        }
        else
        {
            Console.WriteLine("Timed out waiting for work " +
                "method to signal.");
        }
        Console.WriteLine("Main ending.");
    }

    static void WorkMethod(object stateInfo) 
    {
        Console.WriteLine("Work starting.");

        // Simulate time spent working.
        Thread.Sleep(new Random().Next(100, 2000));

        // Signal that work is finished.
        Console.WriteLine("Work ending.");
        ((AutoResetEvent)stateInfo).Set();
    }
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5 SP1, 3.0 SP2, 2.0 SP2

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Show:
© 2014 Microsoft