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JS获取按键的代码,Js如何屏蔽用户的按键,Js获取用户按键对应的ASII码(兼容所有浏览器)

时间:2024-1-22 14:21     作者:韩俊     分类: Javascript


在使用JavaScript做WEB键盘事件侦听捕获时,主要采用onkeypress,onkeydown,onkeyup三个事件,这三个事件执行的顺序为:onkeydown,onkeypress,onkeyup,在一般情况下,采用三种键盘事件均可对键盘输入进行有效的响应,但实际应用的时候会有些许差异,onkeypress事件不能对系统功能键(例如:删除,后退等,其中对中文输入法不能有效的响应)进行正常的响应,onkeydown和onkeyup均可以对系统功能键进行有效的拦截,但事件捕获的位置不同,可以根据具体的情况选择不同的键盘事件。

由于onkeypress不能对系统功能键进行捕获,导致window.event对象的keyCode属性和onkeydown,onkeyup键盘事件中获取的keyCode属性不同,主要表现在onkeypress事件的keyCode对字母的大小写敏感,而onkeydown、onkeyup事件不敏感;onkeypress事件的keyCode无法区分主键盘上的数字键和付键盘数字键的,而onkeydown、onkeyup的keyCode对主付键盘的数字键敏感。

js判断用户按下的按键,根据按下的按键然后执行不同的操作:

document.body.onkeydown=window.onkeydown=function(e){
    var keyCode;
    if(!e) e=window.event;
    if(document.all){
        keyCode=e.keyCode;
    }else{
        keyCode=e.which;
    }
    if(keyCode==37){
        window.location.href="http://www.maopiaopiao.com";
    }
    if(keyCode==39||keyCode==13){
        window.location.href="http://www.maopiaopiao.com";
    }
}

js如何屏蔽用户输入的各种按键呢?请看下面的例子:

function KeyDown(){
    if((window.event.altKey)&&((window.event.keyCode==37)||(window.event.keyCode==39))){
        //屏蔽 Alt+ 方向键 → alert("不准你使用ALT+方向键前进或后退网页!");
        event.returnValue=false;
    }
    if((event.keyCode==8)||(event.keyCode==116)){
        //屏蔽 F5 刷新键
        event.keyCode=0;
        event.returnValue=false;
    }
    if((event.ctrlKey)&&(event.keyCode==78)){
        //屏蔽 Ctrl+n
        event.returnValue=false;
    }
    if((event.shiftKey)&&(event.keyCode==121)){
        //屏蔽 shift+F10
        event.returnValue=false;
    }if(event.keyCode==122){
        //屏蔽 F11
        event.returnValue=false;
    }
}

键盘各种按键对应的ASII码如下:

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 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,则可以利用event.ctrlKey,event.shiftKey,event .altKey判断是否按下了ctrl键、shift键以及alt键

标签: javascript

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