如何利用微信JSSDK调用微信扫一扫功能？具体内容如下

1. 确保有 调起微信扫一扫接口 权限，测试号可能不行；

2. 导入相关JS

<script type="text/javascript" http://test.com/zepto_touch.js"></script> 
<script type="text/javascript" src="http://res.wx.qq.com/open/js/jweixin-1.0.0.js"></script> 

3. 页面触发扫码元素

<img src="../../../images/right.jpg" onclick="scanCode()" class="img"> 

4. 相关JS代码

<script type="text/javascript"> 
 var _appId = "wxz88dbd30e5580e59"; 
 var _data = { 
 appId : _appId, 
 url : location.href, 
 t : Math.random() 
 }; 
 var _getWechatSignUrl = 'http://test.com/getWechatSign.do'; 
 
 // 获取微信签名 
 $.ajax({ 
 url : _getWechatSignUrl, 
 data : _data, 
 success : function(o) { 
 console.log(o); 
 if (o.returnCode == "00") { 
 wxConfig(o.detail[0].timestamp, o.detail[0].nonceStr, o.detail[0].signature); 
 } 
 } 
 }); 
 function wxConfig(_timestamp, _nonceStr, _signature) { 
 //alert('获取数据：'+_timestamp+'\n'+_nonceStr+'\n'+_signature); 
 console.log('获取数据：' + _timestamp + '\n' + _nonceStr + '\n' + _signature); 
 wx.config({ 
 debug : true, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。 
 appId : _appId, // 必填，公众号的唯一标识 
 timestamp : _timestamp, // 必填，生成签名的时间戳 
 nonceStr : _nonceStr, // 必填，生成签名的随机串 
 signature : _signature,// 必填，签名，见附录1 
 jsApiList : [ 'onMenuShareTimeline', 'onMenuShareAppMessage', 
 'onMenuShareQQ', 'onMenuShareWeibo', 'scanQRCode' ] 
 // 必填，需要使用的JS接口列表，所有JS接口列表见附录2 
 }); 
 } 
 function scanCode() { 
 wx.scanQRCode({ 
 needResult : 1, 
 scanType : [ "qrCode", "barCode" ], 
 success : function(res) { 
 console.log(res) 
 alert(JSON.stringify(res)); 
 var result = res.resultStr; 
 }, 
 fail : function(res) { 
 console.log(res) 
 alert(JSON.stringify(res)); 
 
 } 
 }); 
 } 
</script> 

5. 获取签名接口getWechatSign.do各值生成方式

timestamp

Long timestamp = System.currentTimeMillis() / 1000; 

nonceStr

String nonceStr = RandomStringUtils.randomAlphanumeric(16); 

signature

public static String getSign(String jsapi_ticket, String noncestr, Long timestamp, String url) 
 throws NoSuchAlgorithmException { 
 String shaStr = "jsapi_ticket=" + jsapi_ticket + "&noncestr=" + noncestr + "×tamp=" + timestamp + "&url=" 
 + url; 
 MessageDigest mDigest = MessageDigest.getInstance("SHA1"); 
 byte[] result = mDigest.digest(shaStr.getBytes()); 
 StringBuffer signature = new StringBuffer(); 
 for (int i = 0; i < result.length; i++) { 
 signature.append(Integer.toString((result[i] & 0xff) + 0x100, 16).substring(1)); 
 } 
 return signature.toString(); 
} 

6. 微信参考文档

获取access_token  https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1421140183
获取jsapi_ticket  https://mp.weixin.qq.com/wiki?t=resource/res_main&id=mp1421141115