Monitor.TryEnter Method (Object, Int32)

Attempts, for the specified number of milliseconds, to acquire an exclusive lock on the specified object.

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

public static bool TryEnter (
	Object obj,
	int millisecondsTimeout
public static boolean TryEnter (
	Object obj, 
	int millisecondsTimeout
public static function TryEnter (
	obj : Object, 
	millisecondsTimeout : int
) : boolean



The object on which to acquire the lock.


The number of milliseconds to wait for the lock.

Return Value

true if the current thread acquires the lock; otherwise, false.

Exception typeCondition


The obj parameter is a null reference (Nothing in Visual Basic).


The obj parameter is a value type.


millisecondsTimeout is negative, and not equal to Infinite.

If the millisecondsTimeout parameter equals Infinite, this method is equivalent to Enter. If millisecondsTimeout equals 0, this method is equivalent to TryEnter.


Use Monitor to lock objects (that is, reference types), not value types. For details, see Enter and the conceptual topic Monitors.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, 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