js中获取键盘事件及禁止退格键Backspace处理

<script type="text/javascript" language=JavaScript charset="UTF-8">        document.onkeydown=function(event){              var e = event || window.event || arguments.callee.caller.arguments[0];              if(e && e.keyCode==27){ // 按 Esc                  //要做的事情                }              if(e && e.keyCode==113){ // 按 F2                    //要做的事情                 }                          if(e && e.keyCode==13){ // enter 键                  //要做的事情            }         }; 14 </script>15 只要你定义了这些键的动作，你在浏览器里按下这些键就会响应，兼容目前所有浏览器。

  js 里面的键盘事件经常用到，所以收集了键盘事件对应的键码来分享下：   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   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)alert(“enter!”); 键值对应表 A　　0X65 　U 　　0X85 B　　0X66　 V　　 0X86 C　　0X67　 W　　 0X87 D　　0X68　 X 　　0X88 E　　0X69　 Y　　 0X89 F　　0X70　 Z　　 0X90 G　　0X71　 0　　 0X48 H　　0X72　 1　　 0X49 I　　0X73　 2　　 0X50 J　　0X74　 3 　　0X51 K　　0X75　 4 　　0X52 L　　0X76　 5 　　0X53 M　　0X77　 6　　 0X54 N　　0X78 　7 　　0X55 O　　0X79 　8 　　0X56 P　　0X80 　9 　　0X57 Q　　0X81　ESC　　0X1B R　　0X82　CTRL 　0X11 S　　0X83　SHIFT　0X10 T　　0X84　ENTER　0XD 如果要使用组合键，则可以判断是否同时按下了这几个键，比如ctrl键、shift键以及alt键的组合使用就可以判断是否多按下了ctrl键、shift键以及alt键

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js 屏蔽Backspace事件

function document.onkeydown() {if (event.keyCode == 8) { if (document.activeElement.type == "text") {if (document.activeElement.readOnly == false)return true; } return false;}}