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Monitor.TryEnter Method (Object, TimeSpan)

Attempts, for the specified amount of time, to acquire an exclusive lock on the specified object.

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

static bool TryEnter (
	Object^ obj, 
	TimeSpan timeout
public static boolean TryEnter (
	Object obj, 
	TimeSpan timeout
public static function TryEnter (
	obj : Object, 
	timeout : TimeSpan
) : boolean
Not applicable.



The object on which to acquire the lock.


A TimeSpan representing the amount of time to wait for the lock. A value of –1 millisecond specifies an infinite wait.

Return Value

true if the current thread acquires the lock without blocking; otherwise, false.

Exception typeCondition


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


The value of timeout in milliseconds is negative and is not equal to Infinite (–1 millisecond), or is greater than MaxValue.

If the value of the timeout parameter converted to milliseconds equals –1, this method is equivalent to Enter. If the value of timeout 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 Monitor.

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0