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ToggleButton.IsChecked Property

Gets or sets whether the ToggleButton is checked.

Namespace:  System.Windows.Controls.Primitives
Assembly:  PresentationFramework (in PresentationFramework.dll)

[<LocalizabilityAttribute(LocalizationCategory.None, Readability = Readability.Unreadable)>]
member IsChecked : Nullable<bool> with get, set

<object IsChecked="Boolean"/>- or -<object IsChecked="{x:Null Markup Extension}"/>

Property Value

Type: System.Nullable(Boolean)
true if the ToggleButton is checked; false if the ToggleButton is unchecked; otherwise a null reference (Nothing in Visual Basic). The default is false.

Identifier field


Metadata properties set to true


A control that inherits from ToggleButton determines its behavior when this property is a null reference (Nothing in Visual Basic).


When the IsThreeState property is set to true, a user can click a CheckBox to pick three possible states. The following table describes the three states of a CheckBox.

State of the CheckBox

Value of IsChecked






a null reference (Nothing in Visual Basic)

If IsThreeState is false, you can still programmatically set this property to a null reference (Nothing in Visual Basic) to put the CheckBox in an indeterminate state, but the user cannot set the CheckBox to the indeterminate state through the user interface (UI).


If you set this property to a null reference (Nothing in Visual Basic) on a RadioButton, the RadioButton is unchecked.

The following example creates a CheckBox set to an indeterminate state.

<CheckBox Name="checkBox1" IsThreeState="True" 
  A CheckBox in an indeterminate state

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.