一起看看js获取扫码枪输入数据的方法

let code = '';

  let lastTime, nextTime;

  let lastCode, nextCode;

  window.document.onkeypress = (e) => {

   if (window.event) { // IE

    nextCode = e.keyCode;

   } else if (e.which) { // Netscape/Firefox/Opera

    nextCode = e.which;

   }

   if (nextCode === 13) {

    if (code.length < 3) return; // 手动输入的时间不会让code的长度大于2，所以这里只会对扫码枪有

    console.log(code); // 获取到扫码枪输入的内容，做别的操作

    code = '';

    lastCode = '';

    lastTime = '';

    return;

   }

   nextTime = new Date().getTime();

   if (!lastTime && !lastCode) {

    code += e.key;

   }

   if (lastCode && lastTime && nextTime - lastTime > 30) { // 当扫码前有keypress事件时,防止首字缺失

    code = e.key;

   } else if (lastCode && lastTime) {

    code += e.key;

   }

   lastCode = nextCode;

   lastTime = nextTime;

  }