设计步骤

1、在微信管理后台设置可信域名，只能在该域名下调用JS-SDK，域名必须经过备案。

2、新增一个自定义函数，函数名为"GetJsSignature"，用于生成JS-SDK的授权签名，代码为：

Static CreateTime As Date \'记录最近一次生成Ticket 的时间
Static Ticket As String \'记录最近一次生成的Ticket
Dim tp As TimeSpan = Date.Now - CreateTime
Dim ul As String = "https://qyapi.weixin.qq.com/cgi-bin/get_jsapi_ticket?access_token={0}"
If tp.TotalSeconds > 3600 Then
    Dim hc As New HttpClient(CExp(ul,Functions.Execute("GetQYAccessToken")))
    Dim ret As String = hc.GetData()
    If ret = "" Then \'如果失败,再尝试一次
        hc.GetData()
    End If
    CreateTime = Date.Now()
    Dim jo As JObject = JObject.Parse(ret)
    If jo("errcode") = "0" Then
        Ticket = jo("ticket")
    Else
        MessageBox.show("获取jsapi_ticket,原因:" & vbcrlf & jo.ToString)
    End If
End If
Dim signature As String = CExp("jsapi_ticket={0}&noncestr={1}&timestamp={2}&url={3}",Ticket,args(0),args(1),args(2))
Return Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(signature, "SHA1").ToLower()

2、在d:\\web\\lib目录下新建一个文本文件jssdk.js，内容为：

wx.ready(function () {
    document.getElementById(\'scan\').onclick = function () {
        wx.scanQRCode({
            needResult: 1,
            scanType: [\'qrCode\',\'barCode\'],
            success: function (res) {
                document.getElementById(\'number\').value = res.resultStr;
            }
        });
    };
});
wx.error(function (res) {
    //alert(res.errMsg);
});

实际开发的时候，你要变化的只有红色的两处，scan为网页中扫码输入按钮的id，number为网页中产品编号输入框的id。

3、最后将HttpRequest事件代码设置为：

Select Case e.Path
    Case "test.htm",""
        Dim wb As New weui
        wb.AppendHTML("<script src=\'http://res.wx.qq.com/open/js/jweixin-1.0.0.js\'></script>",True) \'引入JS-SDK库
        wb.AppendHTML("<script src=\'./lib/jssdk.js\'></script>") \'引入脚本文件
        \'在页面注入权限验证配置
        Dim st As New Date(1970,1,1,8,0,0)
        Dim appid As String = "wxa31aba4cd83af57e" \'CorpID
        Dim timestamp As Integer = CInt((Date.Now - st).TotalSeconds()) \'时间戳
        Dim noncestr As String = Rand.NextString(16) \'随机字符
        Dim url As String  = e.Request.URL.ToString \'当前页面地址
        Dim signature As String = Functions.Execute("GetJsSignature", noncestr, timestamp, url) \'生成权限验证签名
        Dim cfg As String = "wx.config({appId:\'{0}\',timestamp:{1},nonceStr:\'{2}\',signature:\'{3}\',jsApiList:[\'scanQRCode\']});"
        wb.AppendHTML("<script>" & CExp(cfg,appid,timestamp,noncestr,signature) & "</script>",True)
        \'开始正常生成网页内容
        wb.AddForm("","form1","test.htm")
        With wb.AddInputGroup("form1","ipg1","产品输入")
            .AddInput("product","产品","text")
            With .AddInputCell("ic1")
                .AddLabel("lbh","编号",0)
                .AddInput("number","text",1)
                .AddVcodeButton("scan","扫码输入",2) \'增加二维码扫描按钮,2表示显示在右边
            End With
        End With
        With wb.AddButtonGroup("form1","btg1",True)
            .Add("btn1", "确定", "submit")
        End With
        e.WriteString(wb.Build) \'生成网页
End Select