AppCan——生成Web/微信App版，调用微信JSAPI支付方式，提示WeixinJSBridge内置对象undefined

//    
        function doWxpay(){
            if (typeof(WeixinJSBridge) == "undefined"){
                alert('WeixinJSBridge:undefined');
               if( document.addEventListener ){
                   document.addEventListener('WeixinJSBridgeReady', onBridgeReady, false);
               }else if (document.attachEvent){
                   document.attachEvent('WeixinJSBridgeReady', onBridgeReady); 
                   document.attachEvent('onWeixinJSBridgeReady', onBridgeReady);
               }
            }else{
               onBridgeReady();
            }
        }
        
        function onBridgeReady(){
           WeixinJSBridge.invoke(
               'getBrandWCPayRequest', {
                   "appId" : "wx2421b1c4370ec43b",     //公众号名称，由商户传入     
                   "timeStamp":" 1395712654",         //时间戳，自1970年以来的秒数     
                   "nonceStr" : "e61463f8efa94090b1f366cccfbbb444", //随机串     
                   "package" : "prepay_id=u802345jgfjsdfgsdg888",     
                   "signType" : "MD5",         //微信签名方式:     
                   "paySign" : "70EA570631E4BB79628FBCA90534C63FF7FADD89" //微信签名 
               },
               function(res){     
                   if(res.err_msg == "get_brand_wcpay_request:ok" ) {}     // 使用以上方式判断前端返回,微信团队郑重提示：res.err_msg将在用户支付成功后返回    ok，
               }
           ); 
        }