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Control.IsKeyLocked Method

Determines whether the CAPS LOCK, NUM LOCK, or SCROLL LOCK key is in effect.

Namespace:  System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public static bool IsKeyLocked(
	Keys keyVal


Type: System.Windows.Forms.Keys

The CAPS LOCK, NUM LOCK, or SCROLL LOCK member of the Keys enumeration.

Return Value

Type: System.Boolean
true if the specified key or keys are in effect; otherwise, false.


The keyVal parameter refers to a key other than the CAPS LOCK, NUM LOCK, or SCROLL LOCK key.

Use the IsKeyLocked property to determine whether the CAPS LOCK, NUM LOCK, or SCROLL LOCK keys are on, whether individually or in combination.

The following code example displays a message box indicating whether the specified key (the Caps Lock key in this case) is in effect.

using System;
using System.Windows.Forms;

public class CapsLockIndicator
    public static void Main()
        if (Control.IsKeyLocked(Keys.CapsLock)) {
            MessageBox.Show("The Caps Lock key is ON.");
        else {
            MessageBox.Show("The Caps Lock key is OFF.");

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.

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