本例效果图:


unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs;

type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
procedure MyMsg(var msg: TWMKeyDown); message WM_KEYDOWN;
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
Canvas.Font.Size := 24;
Canvas.Font.Style := [fsBold];
Canvas.Font.Color := clRed;
Canvas.Brush.Color := clWhite;
end;

procedure TForm1.MyMsg(var msg: TWMKeyDown);
var
buf: array[0..31] of Char;
rect: TRect;
str: string;
begin
{获取}
GetKeyNameText(msg.KeyData, buf, Length(buf));
{画出来}
str := buf;
rect := ClientRect;
Canvas.FillRect(rect);
Canvas.TextRect(rect, str, [tfSingleLine, tfCenter, tfVerticalCenter]);
inherited;
end;

end.