键盘控制应用范围非常广泛，比如快捷键控制页面的滚动；在填写表单时候，限制输入内容；或者是屏蔽复制、粘贴、退后等功能。
$(window).keydown(function(event){
switch (event.which) {
case(74): //J键
//要执行的操作
break;
case(75)://K键
//要执行的操作
break;
case(72)://H键
//要执行的操作
break;
case(76)://L键
//要执行的操作
break;
}
});如果要使用组合键，则可以利用event.ctrlKey，event.shiftKey，event .altKey判断是否按下了ctrl键、shift键以及alt键。
下面是键值对照表：
键盘名称 键值（keycode） 键盘名称 键值（keycode）
BackSpace 8 Tab 9
Clear 12 Enter 13
Shift_L 16 Control_L 17
Alt_L 18 Pause 19
Caps_Lock 20 Escape 27
Space 32 Prior 33
Next 34 End 35
Home 36 Left 37
Up 38 Right 39
Down 40 Select 41
Print 42 Execute 43
Insert 45 Delete 46
Help 47 0 equal braceright 48
1 exclam onesuperior 49 2 quotedbl twosuperior 50
3 section threesuperior 51 4 dollar 52
5 percent 53 6 ampersand 54
7 slash braceleft 55 8 parenleft bracketleft 56
9 parenright bracketright 57 a A 65
b B 66 c C 67
d D 68 e E EuroSign 69
f F 70 g G 71
h H 72 i I 73
j J 74 k K 75
l L 76 m M mu 77
n N 78 o O 79
p P 80 q Q at 81
r R 82 s S 83
t T 84 u U 85
v V 86 w W 87
x X 88 y Y 89
z Z 90 KP_0 96
KP_1 97 KP_2 98
KP_3 99 KP_4 100
KP_5 101 KP_6 102
KP_7 103 KP_8 104
KP_9 105 KP_Multiply 106
KP_Add 107 KP_Separator 108
KP_Subtract 109 KP_Decimal 110
KP_Divide 111 F1 112
F2 113 F3 114
F4 115 F5 116
F6 117 F8 119
F9 120 F10 121
F11 122 F12 123
F13 124 F14 125
F15 126 F16 127
F17 128 F18 129
F19 130 F20 131
F21 132 F22 133
F23 134 F24 135
Num_Lock 136 Scroll_Lock 137
Acute grave 187 Comma semicolon 188
Minus underscore 189 Period colon 190
Numbersign apostrophe 192 Plusminus hyphen macron 210
Copyright registered 212 Guillemotleft guillemotright 213
Masculine ordfeminine 214 ae AE 215
Cent yen 216 Questiondown exclamdown 217
Onequarter onehalf threequarters 218 Less greater bar 219
Plus asterisk asciitilde 221 Multiply division 227
acircumflex Acircumflex 228 ecircumflex Ecircumflex 229
icircumflex Icircumflex 230 ocircumflex Ocircumflex 231
ucircumflex Ucircumflex 232 ntilde Ntilde 233
yacute Yacute 234 oslash Ooblique 235
aring Aring 236 ccedilla Ccedilla 237
thorn THORN 238 eth ETH 239
diaeresis cedilla currency 240 agrave Agrave atilde Atilde 241
egrave Egrave 242 igrave Igrave 243
ograve Ograve otilde Otilde 244 ugrave Ugrave 245
adiaeresis Adiaeresis 246 ediaeresis Ediaeresis 247
idiaeresis Idiaeresis 248 odiaeresis Odiaeresis 249
udiaeresis Udiaeresis 250 ssharp question backslash 251
asciicircum degree 252 3 sterling 253
Mode_switch 254
A 0X65 B 0X66
C 0X67 D 0X68
E 0X69 F 0X70
J 0X71 H 0X72
I 0X73 J 0X74
K 0X75 L 0X76
M 0X77 N 0X78
O 0X79 P 0X80
Q 0X81 R 0X82
S 0X83 T 0X84
U 0X85 V 0X86
W 0X87 X 0X88
Y 0X89 Z 0X90
0 0X48 1 0X49
2 0X50 3 0X51
4 0X52 5 0X53
6 0X54 7 0X55
8 0X56 9 0X57
ESC 0X1B CTRL 0X11
SHIFT 0X10 ENTER 0XD