js怎么区分扫码枪输入还是键盘输入

原理是判断数据速度，扫描枪输入速度非常快，几毫秒十几毫秒就完成输入，人工输入就很慢。很多扫描枪会在输入的末尾添加一个回车，也可以用这个作判断。

工具/原料

扫码枪

具体代码如下

1、var code = '';var lastTime, nextTime;var l锾攒揉敫astCode, nextCode;keyboardEvent (keyEvent) { nextCode = keyEvent.keyCode; nextTime = new Date ().getTime (); if (lastCode != null && lastTime != null && nextTime - lastTime <= 30) { code += lastCode - 7; } else if ( lastCode != null && lastTime != null && nextTime - lastTime > 100 ) { code = ''; } lastCode = nextCode; lastTime = nextTime; if (keyEvent.keyCode == 66) { console.log(code) } }