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Task.WaitAny Method (Task[])

Waits for any of the provided Task objects to complete execution.

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

public static int WaitAny(
	params Task[] tasks


Type: System.Threading.Tasks.Task[]
An array of Task instances on which to wait.

Return Value

Type: System.Int32
The index of the completed task in the tasks array argument.


The Task has been disposed.


The tasks argument is null.


The tasks argument contains a null element.

The following example demonstrates using WaitAny to wait for any task in a set of tasks to complete.

// C#

var t1 = Task.Factory.StartNew(() => DoOperation1());

var t2 = Task.Factory.StartNew(() => DoOperation2());

Task.WaitAny(t1, t2)

' Visual Basic

Dim t1 = Task.Factory.StartNew(Sub()


End Sub)

Dim t2 = Task.Factory.StartNew(Sub()


End Sub)

Task.WaitAny(t1, t2)

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, 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.