js读取usb扫码枪数据

window.onload = function () {// 获取扫描的二维码
  var code = "";
  var lastTime, nextTime;
  var lastCode, nextCode;
  document.onkeypress = function (e) {
      nextCode = e.which;
      nextTime = new Date().getTime();

      if (lastCode != null && lastTime != null && nextTime - lastTime <= 30) {
          code += String.fromCharCode(lastCode);
      } else if (lastCode != null && lastTime != null && nextTime - lastTime > 100) {
          code = "";
      }

      lastCode = nextCode;
      lastTime = nextTime;
  }
  this.Template_rendering = function () {
      this.onkeypress = function (e) {
          if (e.which == 13) {
              console.log(code);
              // $('#code').text(code)
              readcode({code: code}); // 调用readcode方法
              code = "";
          }
      }
  }
  this.Template_rendering();
};

标签：nextTime,function,扫码,code,usb,js,var,lastCode,lastTime
来源： https://www.cnblogs.com/binglicheng/p/12923134.html