效果圖：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="ko" lang="ko">
<head>
<title>Javascript 二維碼生成庫：QRCode</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta name="viewport" content="width=device-width,initial-scale=1,user-scalable=no" />
<script type="text/javascript" src="http://static.runoob.com/assets/jquery/2.0.3/jquery.min.js"></script>
<script type="text/javascript" src="http://static.runoob.com/assets/qrcode/qrcode.min.js"></script>
</head>
<body>
輸入你要生成二維碼的內容：<br/>
<input id="text" type="text" value="http://blog.csdn.net/zhongyi_yang" style="width:20%" /><br />
<div id="qrcode" style="width:100px; height:100px; margin-top:15px;"></div>
<script type="text/javascript">
var qrcode = new QRCode(document.getElementById("qrcode"), {
width : 100,
height : 100
});
function makeCode () {
var elText = document.getElementById("text");
if (!elText.value) {
alert("Input a text");
elText.focus();
return;
}
qrcode.makeCode(elText.value);
}
makeCode();
$("#text").
on("blur", function () {
makeCode();
}).
on("keydown", function (e) {
if (e.keyCode == 13) {
makeCode();
}
});
</script>
</body>
</html>