keycode 8 = BackSpace BackSpace
 keycode 9 = Tab Tab
 keycode 12 = Clear
 keycode 13 = Enter
 keycode 16 = Shift_L
 keycode 17 = Control_L
 keycode 18 = Alt_L
 keycode 19 = Pause
 keycode 20 = Caps_Lock
 keycode 27 = Escape Escape
 keycode 32 = space space
 keycode 33 = Prior
 keycode 34 = Next
 keycode 35 = End
 keycode 36 = Home
 keycode 37 = Left
 keycode 38 = Up
 keycode 39 = Right
 keycode 40 = Down
 keycode 41 = Select
 keycode 42 = Print
 keycode 43 = Execute
 keycode 45 = Insert
 keycode 46 = Delete
 keycode 47 = Help
 keycode 48 = 0 equal braceright
 keycode 49 = 1 exclam onesuperior
 keycode 50 = 2 quotedbl twosuperior
 keycode 51 = 3 section threesuperior
 keycode 52 = 4 dollar
 keycode 53 = 5 percent
 keycode 54 = 6 ampersand
 keycode 55 = 7 slash braceleft
 keycode 56 = 8 parenleft bracketleft
 keycode 57 = 9 parenright bracketright
 keycode 65 = a A
 keycode 66 = b B
 keycode 67 = c C
 keycode 68 = d D
 keycode 69 = e E EuroSign
 keycode 70 = f F
 keycode 71 = g G
 keycode 72 = h H
 keycode 73 = i I
 keycode 74 = j J
 keycode 75 = k K
 keycode 76 = l L
 keycode 77 = m M mu
 keycode 78 = n N
 keycode 79 = o O
 keycode 80 = p P
 keycode 81 = q Q at
 keycode 82 = r R
 keycode 83 = s S
 keycode 84 = t T
 keycode 85 = u U
 keycode 86 = v V
 keycode 87 = w W
 keycode 88 = x X
 keycode 89 = y Y
 keycode 90 = z Z
 keycode 96 = KP_0 KP_0
 keycode 97 = KP_1 KP_1
 keycode 98 = KP_2 KP_2
 keycode 99 = KP_3 KP_3
 keycode 100 = KP_4 KP_4
 keycode 101 = KP_5 KP_5
 keycode 102 = KP_6 KP_6
 keycode 103 = KP_7 KP_7
 keycode 104 = KP_8 KP_8
 keycode 105 = KP_9 KP_9
 keycode 106 = KP_Multiply KP_Multiply
 keycode 107 = KP_Add KP_Add
 keycode 108 = KP_Separator KP_Separator
 keycode 109 = KP_Subtract KP_Subtract
 keycode 110 = KP_Decimal KP_Decimal
 keycode 111 = KP_Divide KP_Divide
 keycode 112 = F1
 keycode 113 = F2
 keycode 114 = F3
 keycode 115 = F4
 keycode 116 = F5
 keycode 117 = F6
 keycode 118 = F7
 keycode 119 = F8
 keycode 120 = F9
 keycode 121 = F10
 keycode 122 = F11
 keycode 123 = F12
 keycode 124 = F13
 keycode 125 = F14
 keycode 126 = F15
 keycode 127 = F16
 keycode 128 = F17
 keycode 129 = F18
 keycode 130 = F19
 keycode 131 = F20
 keycode 132 = F21
 keycode 133 = F22
 keycode 134 = F23
 keycode 135 = F24
 keycode 136 = Num_Lock
 keycode 137 = Scroll_Lock
 keycode 187 = acute grave
 keycode 188 = comma semicolon
 keycode 189 = minus underscore
 keycode 190 = period colon
 keycode 192 = numbersign apostrophe
 keycode 210 = plusminus hyphen macron
 keycode 211 =
 keycode 212 = copyright registered
 keycode 213 = guillemotleft guillemotright
 keycode 214 = masculine ordfeminine
 keycode 215 = ae AE
 keycode 216 = cent yen
 keycode 217 = questiondown exclamdown
 keycode 218 = onequarter onehalf threequarters
 keycode 220 = less greater bar
 keycode 221 = plus asterisk asciitilde
 keycode 227 = multiply division
 keycode 228 = acircumflex Acircumflex
 keycode 229 = ecircumflex Ecircumflex
 keycode 230 = icircumflex Icircumflex
 keycode 231 = ocircumflex Ocircumflex
 keycode 232 = ucircumflex Ucircumflex
 keycode 233 = ntilde Ntilde
 keycode 234 = yacute Yacute
 keycode 235 = oslash Ooblique
 keycode 236 = aring Aring
 keycode 237 = ccedilla Ccedilla
 keycode 238 = thorn THORN
 keycode 239 = eth ETH
 keycode 240 = diaeresis cedilla currency
 keycode 241 = agrave Agrave atilde Atilde
 keycode 242 = egrave Egrave
 keycode 243 = igrave Igrave
 keycode 244 = ograve Ograve otilde Otilde
 keycode 245 = ugrave Ugrave
 keycode 246 = adiaeresis Adiaeresis
 keycode 247 = ediaeresis Ediaeresis
 keycode 248 = idiaeresis Idiaeresis
 keycode 249 = odiaeresis Odiaeresis
 keycode 250 = udiaeresis Udiaeresis
 keycode 251 = ssharp question backslash
 keycode 252 = asciicircum degree
 keycode 253 = 3 sterling
 keycode 254 = Mode_switch
使用方法
$("body").keydown(function(event) {
    var keyCode = event.keyCode;   //keyCode就是获取到的键码
    //之后就可以对每个按键自定义函数操作
    switch (keyCode) {
    case 37:    //左
        break;
    case 38:    //上
        break;
    case 39:    //右
        break;
    case 40:    //下
        break;
    default:
        break;
    }
});









