KeyEventArgs Class
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
| Name | Description | |
|---|---|---|
![]() | KeyEventArgs(Keys) | Initializes a new instance of the KeyEventArgs class. |
| Name | Description | |
|---|---|---|
![]() | Alt | Gets a value indicating whether the ALT key was pressed. |
![]() | Control | Gets a value indicating whether the CTRL key was pressed. |
![]() | Handled | Gets or sets a value indicating whether the event was handled. |
![]() | KeyCode | |
![]() | KeyData | |
![]() | KeyValue | |
![]() | Modifiers | |
![]() | Shift | Gets a value indicating whether the SHIFT key was pressed. |
![]() | SuppressKeyPress | Gets or sets a value indicating whether the key event should be passed on to the underlying control. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Finalize() | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.) |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | MemberwiseClone() | |
![]() | ToString() | 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.
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.
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.
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.


