由于硬件的限制，如果同时按下q键和s键，会连续触发两次键盘事件，所以严格来讲所谓的“非ctrl alt shift的组合键”并不是真正的组合键，只是相当于快速地连续按了两个键而已。要想模拟出组合键的效果，就要用一个全局变量先保存第一次按键键码，然后在第二次时再根据两次的键码来判断是否“同时”按了两个键：

<script>

var ok=0

document.onkeydown=function(e){

   var e=e||window.event

   if((ok==81&&e.keyCode==83)||(ok==83&&e.keyCode==81)){

      console.log("你同时按了q键和s键")

      ok=0

   }else if(e.keyCode==81||e.keyCode==83){

      ok=e.keyCode

      setTimeout("ok=0",300)

   }else{

      ok=0

   }

}

</script>

修改代码中的81和83就可以处理其他的组合键了

可以监听到两个不同的keyCode，a和b不能同时按下，你认为的同时，在计算机看来还是有先后顺序，所以监听到的是a和b都触发了，但每次事件只有一个keyCode，所以你要检测时需要自行记录下状态，keydown记录下按键，keyup再取消这个按键，此时可以判断另一个按键是否在记录中，从而判断两个按键同时按

另外，shift ctrl等这些组合键可以直接在其他按键的事件中获取到状态，不需要自己记录

Js判断键盘按键

window.document.onkeydown = disableRefresh

function disableRefresh(evt){

evt = (evt) ? evt : window.event

if (evt.keyCode) {

if(evt.keyCode == 116){

//do something

}

}

}

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event对象的keyCode属性判断输入的键值

eg：if(event.keyCode==13){

var ieKey=event.keyCode//获得键值，数字形式的

var realkey=String.fromCharCode(ieKey) //将数字形式的键值转化为真实的按键

alert(realkey)

}

键值对应表

A0X65 　U 0X85

B0X66　 V 0X86

C0X67　 W 0X87

D0X68　 X 0X88

E0X69　 Y 0X89

F0X70　 Z 0X90

G0X71　 0 0X48

H0X72　 1 0X49

I0X73　 2 0X50

J0X74　 3 0X51

K0X75　 4 0X52

L0X76　 5 0X53

M0X77　 6 0X54

N0X78 　7 0X55

O0X79 　8 0X56

P0X80 　9 0X57

Q0X81　ESC0X1B

R0X82　CTRL 　0X11

S0X83　SHIFT　0X10

T0X84　ENTER　0XD

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

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