html,js获取扫码设备的输入内容

<script type="text/javascript"><!--

window.onload = function () {// 获取扫描的二维码内容

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) {// 扫码枪

code += String.fromCharCode(lastCode);

} else if (lastCode != null && lastTime != null && nextTime - lastTime > 100) { // 键盘

code = "";

}

lastCode = nextCode;

lastTime = nextTime;

}

this.doscan = function () {

this.onkeypress = function (e) {

if (e.which == 13) {

console.log(code);

console.log(code.length);

//后续代码

code = "";

}

}

}

this.doscan();

};

//--></script>