微信支付主要就是三步：1.组装数据生成预支付ID，2.调起微信支付接口，3.结果处理

1. $("#getBrandWCPayRequest").click(function() {  
   $.ajax({  
   type : "POST",  
   url : "",  
   data : {  
   "openId" : $("#openId").val(),  
   "total_fee" : $("#total_price").html(),  
   "body" : $("#bodydes").html(),  
   "productid" : $("#productid").val()  
   }, //参数自己根据业务定义  
   dataType : "json",  
   success : function(data) {  
   callPay(data);  
   }  
   });  
   });  
     
     
   function callPay(data){  
   //alert("回调执行");  
   var appId = data.appId;  
   var timeStamp = data.timeStamp;  
   var nonceStr = data.nonceStr;  
   var package = data.package;  
   var signType = data.signType;  
   var paySign = data.paySign;  
   //  
   WeixinJSBridge.invoke('getBrandWCPayRequest',  
   {  
   "appId" : appId,  
   "timeStamp" : timeStamp,  
   "nonceStr" : nonceStr,  
   "package" : package,  
   "signType" : signType,  
   "paySign" : paySign  
     
   },  
   function(res) {  
   //alert(res.err_msg);  
   WeixinJSBridge.log(res.err_msg);  
   if (res.err_msg == "get_brand_wcpay_request:ok") {  
   //var pc = data.total_fee;  
   //var body = data.body;  
   //var openId = data.openId;  
   //var timeStamp = data.timeStamp;  
   //alert("交易金额:"+pc+"分钱"+"产品名称："+body+"用户openID："+openId+"订单号:2015"+timeStamp);  
   //alert("支付成功!");  
         WeixinJSBridge.call('closeWindow');  
   } else if (res.err_msg == "get_brand_wcpay_request:cancel") {  
   //alert("用户取消支付!");  
   //WeixinJSBridge.call('closeWindow');  
   } else {  
              alert("支付失败!");  
             WeixinJSBridge.call('closeWindow');  
   }  
   });  
     
   }