Control.KeyUp Event (System.Windows.Forms)

KeyUp Event

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

Control..::.KeyUp Event

Updated: November 2007

Occurs when a key is released while the control has focus.

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

Syntax

Visual Basic (Declaration)

Public Event KeyUp As KeyEventHandler

Visual Basic (Usage)

Dim instance As Control
Dim handler As KeyEventHandler

AddHandler instance.KeyUp, handler

public event KeyEventHandler KeyUp

Visual C++

public:
 event KeyEventHandler^ KeyUp {
    void add (KeyEventHandler^ value);
    void remove (KeyEventHandler^ value);
}

/** @event */
public void add_KeyUp (KeyEventHandler value)
/** @event */
public void remove_KeyUp (KeyEventHandler value)

JScript

JScript does not support events.

Remarks

Key events occur in the following order:

To handle keyboard events only at the form level and not enable other controls to receive keyboard events, set the KeyPressEventArgs..::.Handled property in your form's KeyPress event-handling method to true. Certain keys, such as the TAB, RETURN, ESCAPE, and arrow keys are handled by controls automatically. To have these keys raise the KeyUp event, you must override the IsInputKey method in each control on your form. The code for the override of IsInputKey would need to determine if one of the special keys is pressed and return a value of true.

For more information about handling events, see Consuming Events.

Examples

The following code example uses the KeyUp event with the Help class to display pop-up style help to the user.

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 handler 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

// 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 handler 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));
    }
}

Visual 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 handler 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", Point(textBox1->Right,this->textBox1->Bottom) );
      }
   }

// 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 handler 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.get_KeyCode().Equals(Keys.F1)) {
        // Display a pop-up help topic to assist the user.
        Help.ShowPopup(textBox1, "Enter your first name", 
            new Point(textBox1.get_Right(), this.textBox1.get_Bottom()));
    }
} //textBox1_KeyUp

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information