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Control.KeyUp Event

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

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

public event KeyEventHandler KeyUp

Key events occur in the following order:

  1. KeyDown

  2. KeyPress

  3. KeyUp

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, ESC, 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.

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


// 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));
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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