我想得到按键的键盘返回码，怎么实现？(20分)

比如我按了键盘上的‘A’（没同时按shift）应该返回’97‘，
按’1‘应该返回49等。怎么实现呢？

OnKeyDown事件

procedure Tform1.Edit1KeyPress(Sender: TObject;
var Key: Char);
begin
showmessage(inttostr(Ord(Key)));
end;

procedure TForm1.FormKeyDown(Sender: TObject;
var Key: Word;
Shift: TShiftState);
begin
showmessage(inttostr(key));
end;

to:kingdeezj
我得到了几乎所有按键的返回码，但有些我还得不到，比如TAB的返回码。顺便问一下
editkeypress 和 editkeyDown 有什么区别？

to johnrain:
{ Virtual Keys, Standard Set }
{$EXTERNALSYM VK_LBUTTON}
VK_LBUTTON = 1;
{$EXTERNALSYM VK_RBUTTON}
VK_RBUTTON = 2;
{$EXTERNALSYM VK_CANCEL}
VK_CANCEL = 3;
{$EXTERNALSYM VK_MBUTTON}
VK_MBUTTON = 4;
{ NOT contiguous with L &
RBUTTON }
{$EXTERNALSYM VK_BACK}
VK_BACK = 8;
{$EXTERNALSYM VK_TAB}
VK_TAB = 9;
{$EXTERNALSYM VK_CLEAR}
VK_CLEAR = 12;
{$EXTERNALSYM VK_RETURN}
VK_RETURN = 13;
{$EXTERNALSYM VK_SHIFT}
VK_SHIFT = $10;
{$EXTERNALSYM VK_CONTROL}
VK_CONTROL = 17;
{$EXTERNALSYM VK_MENU}
VK_MENU = 18;
{$EXTERNALSYM VK_PAUSE}
VK_PAUSE = 19;
{$EXTERNALSYM VK_CAPITAL}
VK_CAPITAL = 20;
{$EXTERNALSYM VK_KANA }
VK_KANA = 21;
{$EXTERNALSYM VK_HANGUL }
VK_HANGUL = 21;
{$EXTERNALSYM VK_JUNJA }
VK_JUNJA = 23;
{$EXTERNALSYM VK_FINAL }
VK_FINAL = 24;
{$EXTERNALSYM VK_HANJA }
VK_HANJA = 25;
{$EXTERNALSYM VK_KANJI }
VK_KANJI = 25;
{$EXTERNALSYM VK_CONVERT }
VK_CONVERT = 28;
{$EXTERNALSYM VK_NONCONVERT }
VK_NONCONVERT = 29;
{$EXTERNALSYM VK_ACCEPT }
VK_ACCEPT = 30;
{$EXTERNALSYM VK_MODECHANGE }
VK_MODECHANGE = 31;
{$EXTERNALSYM VK_ESCAPE}
VK_ESCAPE = 27;
{$EXTERNALSYM VK_SPACE}
VK_SPACE = $20;
{$EXTERNALSYM VK_PRIOR}
VK_PRIOR = 33;
{$EXTERNALSYM VK_NEXT}
VK_NEXT = 34;
{$EXTERNALSYM VK_END}
VK_END = 35;
{$EXTERNALSYM VK_HOME}
VK_HOME = 36;
{$EXTERNALSYM VK_LEFT}
VK_LEFT = 37;
{$EXTERNALSYM VK_UP}
VK_UP = 38;
{$EXTERNALSYM VK_RIGHT}
VK_RIGHT = 39;
{$EXTERNALSYM VK_DOWN}
VK_DOWN = 40;
{$EXTERNALSYM VK_SELECT}
VK_SELECT = 41;
{$EXTERNALSYM VK_PRINT}
VK_PRINT = 42;
{$EXTERNALSYM VK_EXECUTE}
VK_EXECUTE = 43;
{$EXTERNALSYM VK_SNAPSHOT}
VK_SNAPSHOT = 44;
{$EXTERNALSYM VK_INSERT}
VK_INSERT = 45;
{$EXTERNALSYM VK_DELETE}
VK_DELETE = 46;
{$EXTERNALSYM VK_HELP}
VK_HELP = 47;
{ VK_0 thru VK_9 are the same as ASCII '0' thru '9' ($30 - $39) }
{ VK_A thru VK_Z are the same as ASCII 'A' thru 'Z' ($41 - $5A) }
{$EXTERNALSYM VK_LWIN}
VK_LWIN = 91;
{$EXTERNALSYM VK_RWIN}
VK_RWIN = 92;
{$EXTERNALSYM VK_APPS}
VK_APPS = 93;
{$EXTERNALSYM VK_NUMPAD0}
VK_NUMPAD0 = 96;
{$EXTERNALSYM VK_NUMPAD1}
VK_NUMPAD1 = 97;
{$EXTERNALSYM VK_NUMPAD2}
VK_NUMPAD2 = 98;
{$EXTERNALSYM VK_NUMPAD3}
VK_NUMPAD3 = 99;
{$EXTERNALSYM VK_NUMPAD4}
VK_NUMPAD4 = 100;
{$EXTERNALSYM VK_NUMPAD5}
VK_NUMPAD5 = 101;
{$EXTERNALSYM VK_NUMPAD6}
VK_NUMPAD6 = 102;
{$EXTERNALSYM VK_NUMPAD7}
VK_NUMPAD7 = 103;
{$EXTERNALSYM VK_NUMPAD8}
VK_NUMPAD8 = 104;
{$EXTERNALSYM VK_NUMPAD9}
VK_NUMPAD9 = 105;
{$EXTERNALSYM VK_MULTIPLY}
VK_MULTIPLY = 106;
{$EXTERNALSYM VK_ADD}
VK_ADD = 107;
{$EXTERNALSYM VK_SEPARATOR}
VK_SEPARATOR = 108;
{$EXTERNALSYM VK_SUBTRACT}
VK_SUBTRACT = 109;
{$EXTERNALSYM VK_DECIMAL}
VK_DECIMAL = 110;
{$EXTERNALSYM VK_DIVIDE}
VK_DIVIDE = 111;
{$EXTERNALSYM VK_F1}
VK_F1 = 112;
{$EXTERNALSYM VK_F2}
VK_F2 = 113;
{$EXTERNALSYM VK_F3}
VK_F3 = 114;
{$EXTERNALSYM VK_F4}
VK_F4 = 115;
{$EXTERNALSYM VK_F5}
VK_F5 = 116;
{$EXTERNALSYM VK_F6}
VK_F6 = 117;
{$EXTERNALSYM VK_F7}
VK_F7 = 118;
{$EXTERNALSYM VK_F8}
VK_F8 = 119;
{$EXTERNALSYM VK_F9}
VK_F9 = 120;
{$EXTERNALSYM VK_F10}
VK_F10 = 121;
{$EXTERNALSYM VK_F11}
VK_F11 = 122;
{$EXTERNALSYM VK_F12}
VK_F12 = 123;
{$EXTERNALSYM VK_F13}
VK_F13 = 124;
{$EXTERNALSYM VK_F14}
VK_F14 = 125;
{$EXTERNALSYM VK_F15}
VK_F15 = 126;
{$EXTERNALSYM VK_F16}
VK_F16 = 127;
{$EXTERNALSYM VK_F17}
VK_F17 = 128;
{$EXTERNALSYM VK_F18}
VK_F18 = 129;
{$EXTERNALSYM VK_F19}
VK_F19 = 130;
{$EXTERNALSYM VK_F20}
VK_F20 = 131;
{$EXTERNALSYM VK_F21}
VK_F21 = 132;
{$EXTERNALSYM VK_F22}
VK_F22 = 133;
{$EXTERNALSYM VK_F23}
VK_F23 = 134;
{$EXTERNALSYM VK_F24}
VK_F24 = 135;
{$EXTERNALSYM VK_NUMLOCK}
VK_NUMLOCK = 144;
{$EXTERNALSYM VK_SCROLL}
VK_SCROLL = 145;
{ VK_L &
VK_R - left and right Alt, Ctrl and Shift virtual keys.
Used only as parameters to GetAsyncKeyState() and GetKeyState().
No other API or message will distinguish left and right keys in this way. }
{$EXTERNALSYM VK_LSHIFT}
VK_LSHIFT = 160;
{$EXTERNALSYM VK_RSHIFT}
VK_RSHIFT = 161;
{$EXTERNALSYM VK_LCONTROL}
VK_LCONTROL = 162;
{$EXTERNALSYM VK_RCONTROL}
VK_RCONTROL = 163;
{$EXTERNALSYM VK_LMENU}
VK_LMENU = 164;
{$EXTERNALSYM VK_RMENU}
VK_RMENU = 165;
{$EXTERNALSYM VK_PROCESSKEY}
VK_PROCESSKEY = 229;
{$EXTERNALSYM VK_ATTN}
VK_ATTN = 246;
{$EXTERNALSYM VK_CRSEL}
VK_CRSEL = 247;
{$EXTERNALSYM VK_EXSEL}
VK_EXSEL = 248;
{$EXTERNALSYM VK_EREOF}
VK_EREOF = 249;
{$EXTERNALSYM VK_PLAY}
VK_PLAY = 250;
{$EXTERNALSYM VK_ZOOM}
VK_ZOOM = 251;
{$EXTERNALSYM VK_NONAME}
VK_NONAME = 252;
{$EXTERNALSYM VK_PA1}
VK_PA1 = 253;
{$EXTERNALSYM VK_OEM_CLEAR}
VK_OEM_CLEAR = 254;
以上是所有键的对应值。

至于它们的区别吧，主要是参数的不同吧。KeyDown是一个重载的方法。它包含了对SHIFT键
是否也同时被按下进行检测。至于参数Key的类型不同。参照类型CHAR和WORD的区别。
BTW：我也是DELPHI新手，有机会多交流交流。

多人接受答案了。