Control.OnKeyUp Method
Raises the KeyUp event.
[Visual Basic] Protected Overridable Sub OnKeyUp( _ ByVal e As KeyEventArgs _ ) [C#] protected virtual void OnKeyUp( KeyEventArgs e ); [C++] protected: virtual void OnKeyUp( KeyEventArgs* e ); [JScript] protected function OnKeyUp( e : KeyEventArgs );
Parameters
- e
- A KeyEventArgs that contains the event data.
Remarks
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
The OnKeyUp method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.
Notes to Inheritors: When overriding OnKeyUp in a derived class, be sure to call the base class's OnKeyUp method so that registered delegates receive the event.
Example
[Visual Basic] ' This example demonstrates how to use the KeyUp event with the Help class to display ' pop-up style help to the user of the application. When the user presses F1, the Help ' class displays a pop-up window, similar to a ToolTip, near the control. This example assumes ' that a TextBox control, named textBox1, has been added to the form and its KeyUp ' event has been contected to this event handling method. Private Sub textBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles textBox1.KeyUp ' Determine whether the key entered is the F1 key. Display help if it is. If e.KeyCode = Keys.F1 Then ' Display a pop-up help topic to assist the user. Help.ShowPopup(textBox1, "Enter your first name", New Point(textBox1.Right, Me.textBox1.Bottom)) End If End Sub 'textBox1_KeyUp [C#] // This example demonstrates how to use the KeyUp event with the Help class to display // pop-up style help to the user of the application. When the user presses F1, the Help // class displays a pop-up window, similar to a ToolTip, near the control. This example assumes // that a TextBox control, named textBox1, has been added to the form and its KeyUp // event has been contected to this event handling method. private void textBox1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e) { // Determine whether the key entered is the F1 key. Display help if it is. if(e.KeyCode == Keys.F1) { // Display a pop-up help topic to assist the user. Help.ShowPopup(textBox1, "Enter your first name", new Point(textBox1.Right, this.textBox1.Bottom)); } } [C++] // This example demonstrates how to use the KeyUp event with the Help class to display // pop-up style help to the user of the application. When the user presses F1, the Help // class displays a pop-up window, similar to a ToolTip, near the control. This example assumes // that a TextBox control, named textBox1, has been added to the form and its KeyUp // event has been connected to this event handling method. private: void textBox1_KeyUp(Object* /*sender*/, System::Windows::Forms::KeyEventArgs* e) { // Determine whether the key entered is the F1 key. Display help if it is. if(e->KeyCode == Keys::F1) { // Display a pop-up help topic to assist the user. Help::ShowPopup(textBox1, S"Enter your first name", Point(textBox1->Right, this->textBox1->Bottom)); } }
[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework
See Also
Control Class | Control Members | System.Windows.Forms Namespace | KeyUp