KeyPressEventArgs Class


Provides data for the KeyPress event.

public ref class KeyPressEventArgs : EventArgs
public class KeyPressEventArgs : EventArgs
type KeyPressEventArgs = class
    inherit EventArgs
Public Class KeyPressEventArgs
Inherits EventArgs


The following example illustrates using the KeyPressEventArgs to count keys as they are pressed and to display the results after each key press. Handled is then set to true to keep the operating system from further processing the key. The example assumes a form with a TextBox placed on it.

public ref class myKeyPressClass
   static long keyPressCount = 0;
   static long backspacePressed = 0;
   static long returnPressed = 0;
   static long escPressed = 0;
   TextBox^ textBox1;
   void myKeyCounter( Object^ sender, KeyPressEventArgs^ ex )
      switch ( ex->KeyChar )
            // Counts the backspaces.
         case '\b':
         backspacePressed = backspacePressed + 1;

            // Counts the ENTER keys.
         case '\r':
         returnPressed = returnPressed + 1;

            // Counts the ESC keys.  
         case (char)27:
         escPressed = escPressed + 1;
            // Counts all other keys.
         keyPressCount = keyPressCount + 1;
      textBox1->Text = String::Concat( 
         backspacePressed, " backspaces pressed\r\n",
         escPressed, " escapes pressed\r\n",
         returnPressed, " returns pressed\r\n",
         keyPressCount, " other keys pressed\r\n" );
      ex->Handled = true;
public class myKeyPressClass 
     static long keyPressCount = 0 ;
     static long backspacePressed =  0;
     static long returnPressed = 0 ;
     static long escPressed = 0 ;
     private TextBox textBox1 = new TextBox();
     private void myKeyCounter(object sender, KeyPressEventArgs ex)
             // Counts the backspaces.
         case '\b':
         backspacePressed = backspacePressed + 1;
         break ;
             // Counts the ENTER keys.
         case '\r':
         returnPressed = returnPressed + 1 ;
         break ;
             // Counts the ESC keys.  
         case (char)27:
         escPressed = escPressed + 1 ;
         break ;
             // Counts all other keys.
         keyPressCount = keyPressCount + 1 ;
     textBox1.Text = 
         backspacePressed + " backspaces pressed\r\n" + 
         escPressed + " escapes pressed\r\n" +
         returnPressed + " returns pressed\r\n" +
         keyPressCount + " other keys pressed\r\n" ;
     ex.Handled = true ;
Public Class myKeyPressClass
    Private Shared keyPressCount As Long = 0
    Private Shared backspacePressed As Long = 0
    Private Shared returnPressed As Long = 0
    Private Shared escPressed As Long = 0
    Private textBox1 As TextBox
    Private Sub myKeyCounter(sender As Object, ex As KeyPressEventArgs)
        Select Case ex.KeyChar
            ' Counts the backspaces.
            Case ControlChars.Back
                backspacePressed = backspacePressed + 1
            ' Counts the ENTER keys.
            Case ControlChars.Lf
                returnPressed = returnPressed + 1
            ' Counts the ESC keys.  
            Case Convert.ToChar(27)
                escPressed = escPressed + 1
            ' Counts all other keys.
            Case Else
                keyPressCount = keyPressCount + 1
        End Select
        textBox1.Text = backspacePressed & " backspaces pressed" & _
            ControlChars.Lf & ControlChars.Cr & escPressed & _
            " escapes pressed" & ControlChars.CrLf & returnPressed & _
            " returns pressed" & ControlChars.CrLf & keyPressCount & _
            " other keys pressed" & ControlChars.CrLf
        ex.Handled = True
    End Sub
End Class

You must create a new instance of this class. You must also set the event handler. You can do this in the constructor for your class.

   myKeyPressClass^ myKeyPressHandler;

      myKeyPressHandler = gcnew myKeyPressClass;


      textBox1->KeyPress += gcnew KeyPressEventHandler(
         myKeyPressHandler, &myKeyPressClass::myKeyCounter );
myKeyPressClass myKeyPressHandler = new myKeyPressClass();
public Form1()
     textBox1.KeyPress += new KeyPressEventHandler(myKeyPressHandler.myKeyCounter);
Private myKeyPressHandler As New myKeyPressClass()

Public Sub New()
    AddHandler textBox1.KeyPress, AddressOf myKeyPressHandler.myKeyCounter
End Sub

When the specified event is raised in the control, the attached method is called and the application can execute code in response to the event.


A KeyPressEventArgs specifies the character that is composed when the user presses a key. For example, when the user presses SHIFT + K, the KeyChar property returns an uppercase K.

A KeyPress event occurs when the user presses a key. Two events that are closely related to the KeyPress event are KeyUp and KeyDown. The KeyDown event precedes each KeyPress event when the user presses a key, and a KeyUp event occurs when the user releases a key. When the user holds down a key, duplicate KeyDown and KeyPress events occur each time the character repeats. One KeyUp event is generated upon release.

With each KeyPress event, a KeyPressEventArgs is passed. A KeyEventArgs is passed with each KeyDown and KeyUp event. A KeyEventArgs specifies whether any modifier keys (CTRL, SHIFT, or ALT) were pressed along with another key. (This modifier information can also be obtained through the ModifierKeys property of the Control class.)

Set Handled to true to cancel the KeyPress event. This keeps the control from processing the key press.


Some controls will process certain key strokes on KeyDown. For example, RichTextBox processes the Enter key before KeyPress is called. In such cases, you cannot cancel the KeyPress event, and must cancel the key stroke from KeyDown instead.

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



Initializes a new instance of the KeyPressEventArgs class.



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


Gets or sets the character corresponding to the key pressed.



Determines whether the specified object is equal to the current object.

(Inherited from Object)

Serves as the default hash function.

(Inherited from Object)

Gets the Type of the current instance.

(Inherited from Object)

Creates a shallow copy of the current Object.

(Inherited from Object)

Returns a string that represents the current object.

(Inherited from Object)

Applies to

See also