KeyEventArgs Class

 

Provides data for the KeyDown or KeyUp event.

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

System.Object
  System.EventArgs
    System.Windows.Forms.KeyEventArgs

[<ComVisibleAttribute(true)>]
type KeyEventArgs = 
    class
        inherit EventArgs
    end

NameDescription
System_CAPS_pubmethodKeyEventArgs(Keys)

Initializes a new instance of the KeyEventArgs class.

NameDescription
System_CAPS_pubpropertyAlt

Gets a value indicating whether the ALT key was pressed.

System_CAPS_pubpropertyControl

Gets a value indicating whether the CTRL key was pressed.

System_CAPS_pubpropertyHandled

Gets or sets a value indicating whether the event was handled.

System_CAPS_pubpropertyKeyCode

Gets the keyboard code for a KeyDown or KeyUp event.

System_CAPS_pubpropertyKeyData

Gets the key data for a KeyDown or KeyUp event.

System_CAPS_pubpropertyKeyValue

Gets the keyboard value for a KeyDown or KeyUp event.

System_CAPS_pubpropertyModifiers

Gets the modifier flags for a KeyDown or KeyUp event. The flags indicate which combination of CTRL, SHIFT, and ALT keys was pressed.

System_CAPS_pubpropertyShift

Gets a value indicating whether the SHIFT key was pressed.

System_CAPS_pubpropertySuppressKeyPress

Gets or sets a value indicating whether the key event should be passed on to the underlying control.

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

A KeyEventArgs, which specifies the key the user pressed and whether any modifier keys (CTRL, ALT, and SHIFT) were pressed at the same time, is passed with each KeyDown or KeyUp event.

The KeyDown event occurs when the user presses any key. The KeyUp event occurs when the user releases the key. Duplicate KeyDown events occur each time the key repeats, if the key is held down, but only one KeyUp event is generated when the user releases the key.

The KeyPress event also occurs when a key is pressed. A KeyPressEventArgs is passed with each KeyPress event, and specifies the character that was composed as a result of each key press.

For information about the event model, see Handling and Raising Events.

The following code examples demonstrate how to detect the state of a key press.

Example 1

The following code example demonstrates how to use the KeyDown event with the Help class to display pop-up style Help to the user of the application. The example uses the KeyEventArgs properties passed to the event handler method to filter for all variations of pressing the F1 key with a modifier key. When the user presses any variation of F1 that includes any keyboard modifier, the Help class displays a pop-up window, similar to a ToolTip, near the control. If the user presses ALT+F2, a different Help pop-up is displayed with additional information.

No code example is currently available or this language may not be supported.

Example 2

The following example determines whether the user pressed ALT+E, and if the mouse pointer is over a TreeNode, allows the user to edit that TreeNode.

No code example is currently available or this language may not be supported.

Example 3

The following example determines whether the user pressed a non-numeric key, and if so, cancels the KeyPress event by using the Handled property.

No code example is currently available or this language may not be supported.

.NET Framework
Available since 1.1

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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