OnKeyPress

Overview

The OnKeyPress event of an object allows you to check what key the user has pressed.

Note that this procedure handles printable characters only. Non-printable characters (e.g. control sequences) are handled by the OnKeyDown event.

Note: OnKeyPress doesn't support Unicode characters. If you need Unicode characters but no control characters, use OnUTF8KeyPress.

Example

uses
  ...LCLType, Dialogs, ...;
  ...  

procedure TMainForm.FormKeyPress(Sender: TObject; var Key: char);
begin
  case key of
    '0': ShowMessage('"0" key pressed');
    '1': ShowMessage('"1" key pressed');
    '2': ShowMessage('"2" key pressed');
  end;
  Key := #0; // Necessary for some widgetsets, e.g. Cocoa, in order to disable processing in subsequent elements.
end;

See also

• LCL Key Handling Detailed background on key handling in the LCL.
• key down

From the Free Pascal wiki, page "OnKeyPress", as it stood on 2020-02-23 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's Licensing page. If you have concerns about this material, message the admin.