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The OnKeyPress client-side event handler is called when the user presses a key and is supported by all RadInput controls.

The event imitates the standard DOM onkeypress event which does not fire for all keys (e.g. ALT, CTRL, SHIFT, ESC) in all browsers, as opposed to the onkeydown event, which works for all keys.

Two parameters are passed to the event handler:

  • sender is the input control.

  • eventArgs has the following methods:

    • set_cancel() lets you prevent the key press from entering a new character into the input control.

    • get_keyCode() returns the key code for the key that was pressed.

    • get_keyCharacter() returns the character that is about to be entered into the input control in response to the key press.

    • get_domEvent() returns the DOM event object for the key press.

The following example uses the OnKeyPress event to limit input to the letters 'a' to 'z' and 'A' to 'Z':

<telerik:RadMaskedTextBox RenderMode="Lightweight" ID="RadMaskedTextBox1" runat="server">
    <ClientEvents OnKeyPress="AlphabetOnly" />
<script type="text/javascript">
    function AlphabetOnly(sender, eventArgs)
        var c = eventArgs.get_keyCode();
        if ((c < 65) || (c > 90 && c < 97) || (c > 122))

During the OnKeyPress event the value is still not updated, therefore, sender.get_value() will return the old one.

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