用jQuery判断当前的按键
做web开发的时候,有时候需要根据键盘进行一些操作,例如按下Enter的时候提交表单,禁止用户输入某些特殊字符,设置快捷键等等。这时候需要找出用户按下的是那些按键,写个小程序来测试按键。
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$(document).ready(function(){
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var $down = $("#down");
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var $press = $("#press");
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var $up = $("#up");
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$(document).keydown(function(event){
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$down.append(String.fromCharCode(event.keyCode) + " ");
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if (event.ctrlKey) {
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alert("ctrl");
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}
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}).keyup(function(event){
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$up.append(String.fromCharCode(event.keyCode) + " ");
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}).keypress(function(event){
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$press.append(String.fromCharCode(event.keyCode) + " ");
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});
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});
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方法是触发down时,把keyCode push到数组里,并删除重复元素;触发up时,用$.grep从数组中删除该keyCode。
在任意时刻,这个数组里都保存了当前所按的按键,并且顺序是根据按键顺序排列的。