Class RadVirtualKeyboardElement

The main element in the RadVirtualKeyboard control that hosts all elements, logic, properties, methods and events for the virtual keyboard functionality.

Inheritance
System.Object
DisposableObject
RadObject
RadElement
VisualElement
RadComponentElement
RadItem
UIItemBase
LightVisualElement
RadVirtualKeyboardElement
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Namespace: Telerik.WinControls.UI
Assembly: Telerik.WinControls.UI.dll

Syntax

public class RadVirtualKeyboardElement : LightVisualElement, INotifyPropertyChanged, ICustomTypeDescriptor, ISupportSystemSkin, IComponent, IDisposable, IBindableComponent, ISupportDrag, ISupportDrop, IShortcutProvider, IStylableElement, IStylableNode, IPrimitiveElement, IShapedElement, IFillElement, IBorderElement, IBoxStyle, IBoxElement, IDrawFillElement, IImageElement, ITextPrimitive, ITextProvider, IUpdateKeysListener, IKeyboardLayoutUpdatedListener, IKeyPressedListener, IVirtualKeyboardKeyInputSender

Constructors

RadVirtualKeyboardElement()

Initializes a new instance of the RadVirtualKeyboardElement class with default settings and registers event listeners.

Declaration
public RadVirtualKeyboardElement()

Properties

ClickSoundStream

Gets or sets the audio stream used for key press sounds. Returns the default sound if no custom stream is set.

Declaration
public Stream ClickSoundStream { get; set; }
Property Value
System.IO.Stream

CurrentCulture

Gets or sets the culture used for keyboard layout and key text generation.

Declaration
public CultureInfo CurrentCulture { get; set; }
Property Value
System.Globalization.CultureInfo

IsAltActive

Gets a value indicating whether the Alt modifier key is currently in active state.

Declaration
public bool IsAltActive { get; }
Property Value
System.Boolean

IsAltGrActive

Gets a value indicating whether the AltGr (right Alt) modifier key is currently in active state.

Declaration
public bool IsAltGrActive { get; }
Property Value
System.Boolean

IsCapsLockOn

Gets a value indicating whether the CapsLock key is currently active system-wide.

Declaration
public static bool IsCapsLockOn { get; }
Property Value
System.Boolean

IsControlActive

Gets a value indicating whether the Control modifier key is currently in active state.

Declaration
public bool IsControlActive { get; }
Property Value
System.Boolean

IsNumLockActive

Gets a value indicating whether the NumLock key is currently in active state.

Declaration
public bool IsNumLockActive { get; }
Property Value
System.Boolean

Implements

IsNumLockOn

Gets a value indicating whether the NumLock key is currently active system-wide.

Declaration
public static bool IsNumLockOn { get; }
Property Value
System.Boolean

IsScrollLockOn

Gets a value indicating whether the ScrollLock key is currently active system-wide.

Declaration
public static bool IsScrollLockOn { get; }
Property Value
System.Boolean

IsShiftActive

Gets a value indicating whether the Shift modifier key is currently in active state.

Declaration
public bool IsShiftActive { get; }
Property Value
System.Boolean

Implements

IsWindowsKeyActive

Gets a value indicating whether the Windows modifier key is currently in active state.

Declaration
public bool IsWindowsKeyActive { get; }
Property Value
System.Boolean

KeyboardLayoutUpdatedListenersList

Gets the collection of objects that implement IKeyboardLayoutUpdatedListener and will be notified when keyboard layout or language changes.

Declaration
public static IList<IKeyboardLayoutUpdatedListener> KeyboardLayoutUpdatedListenersList { get; }
Property Value
System.Collections.Generic.IList<IKeyboardLayoutUpdatedListener>

LanguageCheckTimer

Gets the timer that periodically checks for system language changes and notifies listeners when changes occur.

Declaration
public static Timer LanguageCheckTimer { get; }
Property Value
System.Windows.Forms.Timer

LayoutType

Gets or sets the keyboard layout type which determines the arrangement and availability of keys on the virtual keyboard.

Declaration
public KeyboardLayoutType LayoutType { get; set; }
Property Value
KeyboardLayoutType

MainLayoutPanel

Gets or sets the main layout panel that hosts and arranges the keyboard layouts and key elements.

Declaration
public VirtualKeyboardLayoutPanel MainLayoutPanel { get; set; }
Property Value
VirtualKeyboardLayoutPanel

ModifierKeys

Gets the collection of virtual key codes for currently active modifier keys.

Declaration
public List<int> ModifierKeys { get; }
Property Value
System.Collections.Generic.List<System.Int32>

PreventPopupsAutoClose

Gets or sets a value indicating whether the RadVirtualKeyboard should intercept system mouse clicks on its surface before they are processed by other application pop-ups, context menus, drop-downs, or any other elements that are automatically closed when you click outside of their surface. This prevents these UI elements from closing unexpectedly when users interact with the virtual keyboard, ensuring a seamless typing experience in touch-enabled scenarios.

Declaration
public static bool PreventPopupsAutoClose { get; set; }
Property Value
System.Boolean

true if the virtual keyboard should intercept system mouse events; otherwise, false. The default value is true.
Remarks

When enabled, this feature intercepts system-wide mouse events before they reach other applications. This is particularly important when the RadVirtualKeyboard is used alongside pop-up windows, context menus, or drop-down controls that would normally close when receiving mouse events outside their boundaries. By intercepting these events, the virtual keyboard prevents unintended closures and maintains a consistent user experience.

Note: Enabling this feature disables the repeat button functionality of virtual keyboard keys.

Disabling this feature may result in pop-ups, context menus, and drop-down controls closing unexpectedly when users interact with the virtual keyboard.

ScaleFontOnResize

Gets or sets a value indicating whether the font size should be automatically scaled when the control size changes.

Declaration
public bool ScaleFontOnResize { get; set; }
Property Value
System.Boolean

Implements

SynchronizeCultureWithSystem

Gets or sets a value indicating whether the virtual keyboard will automatically synchronize with system language changes.

Declaration
public bool SynchronizeCultureWithSystem { get; set; }
Property Value
System.Boolean

UpdateKeysListenersList

Gets the collection of objects that implement IUpdateKeysListener and will be notified when CapsLock, NumLock or ScrollLock state changes.

Declaration
public static IList<IUpdateKeysListener> UpdateKeysListenersList { get; }
Property Value
System.Collections.Generic.IList<IUpdateKeysListener>

UseClickSound

Gets or sets a value indicating whether a click sound should be played when keys are pressed.

Declaration
public bool UseClickSound { get; set; }
Property Value
System.Boolean

Methods

DisposeManagedResources()

Releases all managed resources used by the RadVirtualKeyboardElement and removes event listeners.

Declaration
protected override void DisposeManagedResources()
Overrides

DoKeyDown(KeyEventArgs)

This method is not relevant for this element.

Declaration
protected override void DoKeyDown(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

Overrides

DoKeyPress(KeyPressEventArgs)

This method is not relevant for this element.

Declaration
protected override void DoKeyPress(KeyPressEventArgs e)
Parameters
System.Windows.Forms.KeyPressEventArgs e

Overrides

DoKeyUp(KeyEventArgs)

This method is not relevant for this element.

Declaration
protected override void DoKeyUp(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

Overrides

GetLayoutPanelByLayoutType(KeyboardLayoutType)

Returns a VirtualKeyboardLayoutPanel instance with predefined keyboard layout based on the specified layout type.

Declaration
protected virtual VirtualKeyboardLayoutPanel GetLayoutPanelByLayoutType(KeyboardLayoutType value)
Parameters
KeyboardLayoutType value

The keyboard layout type to create a panel for.
Returns
VirtualKeyboardLayoutPanel

A new VirtualKeyboardLayoutPanel instance configured for the specified layout type.

GetTextFromKeyInfo(KeyInfo)

Extracts the appropriate text representation from a KeyInfo object based on current modifier key states.

Declaration
public string GetTextFromKeyInfo(KeyInfo keyInfo)
Parameters
KeyInfo keyInfo

The key information object containing text variants.
Returns
System.String

The text that should be displayed or sent for the key.
Implements

InitializeFields()

Initializes member fields to their default values during element construction.

Declaration
protected override void InitializeFields()
Overrides

OnKeyboardLayoutChanged(VirtualKeyboardLayoutChangedEventArgs)

Raises the KeyboardLayoutChanged event with the specified event arguments.

Declaration
protected virtual void OnKeyboardLayoutChanged(VirtualKeyboardLayoutChangedEventArgs e)
Parameters
VirtualKeyboardLayoutChangedEventArgs e

The event arguments containing layout change information.

OnKeyDown(KeyEventArgs)

This method is not relevant for this element.

Declaration
protected override void OnKeyDown(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

Overrides

OnKeyPress(KeyPressEventArgs)

This method is not relevant for this element.

Declaration
protected override void OnKeyPress(KeyPressEventArgs e)
Parameters
System.Windows.Forms.KeyPressEventArgs e

Overrides

OnKeyPressed(Keys)

Handles key press events from the system and updates lock key states accordingly.

Declaration
public void OnKeyPressed(Keys key)
Parameters
System.Windows.Forms.Keys key

The key that was pressed.
Implements

OnKeyUp(KeyEventArgs)

This method is not relevant for this element.

Declaration
protected override void OnKeyUp(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

Overrides

OnLoaded()

Called when the element has been successfully loaded including all its children.

Declaration
protected override void OnLoaded()
Overrides

OnVirtualKeySending(VirtualKeyboardKeySendingEventArgs)

Raises the KeySending event with the specified event arguments.

Declaration
protected virtual void OnVirtualKeySending(VirtualKeyboardKeySendingEventArgs e)
Parameters
VirtualKeyboardKeySendingEventArgs e

The event arguments containing key sending information.

OnVirtualKeySent(VirtualKeyboardKeySentEventArgs)

Raises the KeySent event with the specified event arguments and plays the click sound if enabled.

Declaration
protected virtual void OnVirtualKeySent(VirtualKeyboardKeySentEventArgs e)
Parameters
VirtualKeyboardKeySentEventArgs e

The event arguments containing key sent information.

PlaySound()

Plays the configured click sound if UseClickSound is enabled.

Declaration
protected virtual void PlaySound()

RaiseKeyDown(KeyEventArgs)

This method is not relevant for this element.

Declaration
protected override void RaiseKeyDown(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

Overrides

RaiseKeyPress(KeyPressEventArgs)

This method is not relevant for this element.

Declaration
protected override void RaiseKeyPress(KeyPressEventArgs e)
Parameters
System.Windows.Forms.KeyPressEventArgs e

Overrides

RaiseKeyUp(KeyEventArgs)

This method is not relevant for this element.

Declaration
protected override void RaiseKeyUp(KeyEventArgs e)
Parameters
System.Windows.Forms.KeyEventArgs e

Overrides

Send(IKey, Char)

Sends a character input to the focused application.

Declaration
public void Send(IKey sender, char symbol)
Parameters
IKey sender

The key instance that initiated the send operation.
System.Char symbol

The character to send.
Implements

Send(IKey, Int32)

Sends a key input using the specified virtual key code to the focused application.

Declaration
public void Send(IKey sender, int virtualKey)
Parameters
IKey sender

The key instance that initiated the send operation.
System.Int32 virtualKey

The virtual key code to send.
Implements

Send(IKey, String)

Sends text input to the focused application.

Declaration
public void Send(IKey sender, string text)
Parameters
IKey sender

The key instance that initiated the send operation.
System.String text

The text string to send.
Implements

Send(IKey, Keys)

Sends a key input using the specified System.Windows.Forms.Keys enumeration value to the focused application.

Declaration
public void Send(IKey sender, Keys key)
Parameters
IKey sender

The key instance that initiated the send operation.
System.Windows.Forms.Keys key

The System.Windows.Forms.Keys value to send.
Implements

SendCore(IKey, KeySendContext, Nullable<Int32>, String)

Core implementation for sending key input with support for both virtual key codes and text.

Declaration
protected virtual void SendCore(IKey sender, KeySendContext context, int? virtualKey = default(int? ), string text = null)
Parameters
IKey sender

The key instance that initiated the send operation.
KeySendContext context

The context indicating whether to send as virtual key or text.
System.Nullable<System.Int32> virtualKey

The virtual key code when sending as virtual key.
System.String text

The text when sending as text.

UpdateKeyboardLayout(CultureInfo)

Handles keyboard layout changes from the system and updates the virtual keyboard accordingly.

Declaration
public void UpdateKeyboardLayout(CultureInfo culture)
Parameters
System.Globalization.CultureInfo culture

The new culture information representing the changed keyboard layout.
Implements

UpdateKeys()

Updates the text and appearance of all keys in the virtual keyboard based on the current culture and modifier key states.

Declaration
public void UpdateKeys()
Implements

UpdateKeysListeners()

Notifies all registered listeners when CapsLock, NumLock or ScrollLock state changes.

Declaration
public static void UpdateKeysListeners()

UpdateModifierKeys(IKey)

Updates the visual state of modifier and lock keys based on the current keyboard state.

Declaration
protected virtual void UpdateModifierKeys(IKey key)
Parameters
IKey key

The key to update the state for.

Events

KeyboardLayoutChanged

Occurs when the keyboard layout or culture changes, providing information about the old and new cultures.

Declaration
public event VirtualKeyboardLayoutChangedEventHandler KeyboardLayoutChanged
Event Type
VirtualKeyboardLayoutChangedEventHandler

KeyDown

This event is not relevant for this element.

Declaration
public event KeyEventHandler KeyDown
Event Type
System.Windows.Forms.KeyEventHandler

KeyPress

This event is not relevant for this element.

Declaration
public event KeyPressEventHandler KeyPress
Event Type
System.Windows.Forms.KeyPressEventHandler

KeySending

Occurs before a key is sent to the target application, allowing cancellation or modification of the key operation.

Declaration
public event VirtualKeyboardKeySendingEventHandler KeySending
Event Type
VirtualKeyboardKeySendingEventHandler

KeySent

Occurs after a key has been successfully sent to the target application.

Declaration
public event VirtualKeyboardKeySentEventHandler KeySent
Event Type
VirtualKeyboardKeySentEventHandler

KeyUp

This event is not relevant for this element.

Declaration
public event KeyEventHandler KeyUp
Event Type
System.Windows.Forms.KeyEventHandler

Explicit Interface Implementations

IKeyPressedListener.OnMouseDown(Point)

Declaration
void IKeyPressedListener.OnMouseDown(Point mousePosition)
Parameters
System.Drawing.Point mousePosition

Implements

IKeyPressedListener.OnMouseUp(Point)

Declaration
void IKeyPressedListener.OnMouseUp(Point mousePosition)
Parameters
System.Drawing.Point mousePosition

Implements

IKeyPressedListener.ShouldInterceptMouseEvents(Point)

Declaration
bool IKeyPressedListener.ShouldInterceptMouseEvents(Point mousePosition)
Parameters
System.Drawing.Point mousePosition

Returns
System.Boolean

Implements

Extension Methods