微信公众号H5支付步骤

微信公众平台：https://mp.weixin.qq.com/

进入 微信支付 管理》开通支付功能。

微信支付|商户平台：

设置安全目录：https://pay.weixin.qq.com/index.php/extend/pay_setting，意思是只有该目录下的页面才能够发起支付请求。

注意保存对应的appid和Appsecret。

接下来是微信的授权js，Authorize.cshtml

<script type="text/javascript">
        var code = GetQueryString("code");
        var state = GetQueryString("state");
        if (code == null || code == undefined || code == "") {
            //步骤1：第一次进入本页面，先获取微信的授权code，然后再跳转会本页面，这时候微信会自动加上code参数
            var REDIRECT_URI = encodeURI("http://www.xxx.com/Home/Authorize");
            var url2 = "https://open.weixin.qq.com/connect/oauth2/authorize?appid=xxxxxx&redirect_uri=" + REDIRECT_URI + "&response_type=code&scope=snsapi_userinfo&state=" + state + "#wechat_redirect";
            window.location.href = url2;
        }
        else {
            //步骤1会重新返回到本页面，并携带code参数，然后进入步骤2：服务器端获取openid
            $.ajax({
                type: "GET",
                url: "/WX/GetToken",
                data: { code: code },
                success: function (result) {
                    var data = $.parseJSON(result);
                    if (data.openid != null && data.openid != "" && data.openid != undefined) {
                        if (data.IsFirst) {
                            window.location.href = "/UInfo/UData?state=" + state;
                        }
                        else {
                            if (state == 1) {
                                window.location.href = "/BInfo/Index";
                            }
                            else if (state == 2) {
                                window.location.href = "/CInfo/Index";
                            }
                            else {
                                window.location.href = "/UInfo/Index";
                            }
                        }
                    }
                    else {
                        alert(data.errmsg);
                    }
                }
            });
        }
    </script>

 服务器端代码：

　　　　　/// <summary>
        /// 微信授权登录，获取微信用户基础数据、生成AccessToken、注册用户,WX/GetToken?code=xxx
        /// </summary>
        /// <param name="code"></param>
        /// <returns></returns>
        [HttpGet]
        public ContentResult GetToken(string code)
        {
            JavaScriptSerializer js = new JavaScriptSerializer();
            try
            {
                //获取token
                WXAuthorizeModel authorizeModel = GetWXAuthorizeInfo(code);

                if (authorizeModel != null && authorizeModel.errcode == 0)
                {
                    //记录token，获取数据库中已存在的该用户的 WX token
                    Models.WXMPTokensInfo tokensInfo = WXMPTokensInfoBLL.GetDataByOpenId(authorizeModel.openid);
                    if (tokensInfo == null)
                    {
                        tokensInfo = new Models.WXMPTokensInfo();
                    }

                    tokensInfo.access_token = authorizeModel.access_token;
                    tokensInfo.CreateDate = DateTime.Now;
                    tokensInfo.EndDate = DateTime.Now.AddSeconds(authorizeModel.expires_in);
                    tokensInfo.expires_in = authorizeModel.expires_in;
                    tokensInfo.openid = authorizeModel.openid;
                    tokensInfo.refresh_token = authorizeModel.refresh_token;
                    tokensInfo.scope = authorizeModel.scope;
                    int no = 0;
                    if (tokensInfo.ID > 0)
                    {
                        no = WXMPTokensInfoBLL.Modify(tokensInfo);
                    }
                    else
                    {
                        no = WXMPTokensInfoBLL.Add(tokensInfo);
                    }
                    //获取微信用户个人资料
                    WXUserInfo wxuserInfo = GetWXUserInfo(authorizeModel.openid);
                    Models.UserInfo userInfo = UserInfoBLL.GetEntityByOpenID(authorizeModel.openid);
                    if (userInfo == null)
                    {
                        userInfo = new Models.UserInfo();
                    }
                    userInfo.city = wxuserInfo.city;
                    userInfo.country = wxuserInfo.country;
                    userInfo.headimgurl = wxuserInfo.headimgurl;
                    userInfo.nickname = wxuserInfo.nickname;
                    userInfo.openid = wxuserInfo.openid;
                    userInfo.privilege = "";//wxuserInfo.privilege;
                    userInfo.province = wxuserInfo.province;
                    userInfo.sex = wxuserInfo.sex;
                    userInfo.unionid = wxuserInfo.unionid;
                    //保存、更新微信用户资料
                    bool isFirst = true;
                    int no2 = 0;
                    if (userInfo.ID > 0)
                    {
                        isFirst = false;
                        no2 = UserInfoBLL.ModifyEntity(userInfo);
                    }
                    else
                    {
                        no2 = UserInfoBLL.Append(userInfo);
                        userInfo.ID = no2;
                    }
                    //设置session
                    Session["UModel"] = userInfo;
                    //设置cookie保存微信openid
                    CookiesHelper.setCookie("openid", authorizeModel.openid, 7);

                    //返回json数据给页面
                    var data = new
                    {
                        authorizeModel.openid,
                        authorizeModel.errcode,
                        authorizeModel.errmsg,
                        IsFirst = isFirst
                    };
                    return Content(js.Serialize(data));
                }
                //token获取失败，返回-1
                return Content(js.Serialize(new { openid = "", errcode = -1, authorizeModel.errmsg }));
            }
            catch (Exception ex)
            {
                Log.Error("GetWXToken", ex.Message);
                return Content(js.Serialize(new { openid = "", errcode = -1, ex.Message }));
            }
        }

获取微信token：

/// <summary>
/// 获取微信授权信息（AccessToken）
/// </summary>
/// <param name="code"></param>
/// <returns></returns>
public WXAuthorizeModel GetWXAuthorizeInfo(string code)
{
    string url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=xxxxxx&secret=xxxxxx&code=" + code + "&grant_type=authorization_code";
    string result = Utils.ClientRequest(url, "", "GET");//这是一个发送Http请求的函数，博客园里很多，自己搜就好了，我以前的文章里也有。

    JavaScriptSerializer js = new JavaScriptSerializer();
    WXAuthorizeModel authorizeModel = js.Deserialize<WXAuthorizeModel>(result);
    return authorizeModel;
}
/// <summary>
/// 获取微信用户数据
/// </summary>
/// <param name="openid"></param>
/// <returns></returns>
public WXUserInfo GetWXUserInfo(string openid)
{
    Models.WXMPTokensInfo tokensInfo = WXMPTokensInfoBLL.GetDataByOpenId(openid);
    if (tokensInfo != null && tokensInfo.EndDate > DateTime.Now)//如果Token的有效期已经过了，则要重新获取Token
    {
        string url = "https://api.weixin.qq.com/sns/userinfo?access_token=" + tokensInfo.access_token + "&openid=" + openid + "&lang=zh_CN";
        string result = Utils.ClientRequest(url, "", "GET");
        JavaScriptSerializer js = new JavaScriptSerializer();
        WXUserInfo wXUser = js.Deserialize<WXUserInfo>(result);
        return wXUser;
    }
    return null;
}

public class WXAuthorizeModel
{
    public string access_token { get; set; }
    public int expires_in { get; set; }
    public string refresh_token { get; set; }
    public string openid { get; set; }
    public string scope { get; set; }
    public int errcode { get; set; }
    public string errmsg { get; set; }
}

微信支付参数和通知：

/// <summary>
        /// 生成微信支付js参数
        /// /WX/GeneralWXPayPara
        /// {"openid":"xxxx"}
        /// openid：微信用户openid；
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        [AcceptVerbs("POST")]
        public ContentResult GeneralWXPayPara(WXPayModel data)
        {
            JavaScriptSerializer js = new JavaScriptSerializer();
            try
            {
                string openid = data.openid;if (!string.IsNullOrEmpty(openid))
                {
                    Models.UserInfo userinfo = UserInfoBLL.GetEntityByOpenID(openid);
                    if (userinfo != null)
                    {
                        int total_fee = 1;//单位：分
                        string body = "test";
                        string attach = "1";//这是用户自定义附加的字符串，在通知接口中会携带返回，很重要，可以传自己业务逻辑的标识。string tradeNo = WxPayApi.GenerateOutTradeNo();//下载的微信SDK中自带的函数
                        //若传递了相关参数，则调统一下单接口，获得后续相关接口的入口参数
                        JsApiPay jsApiPay = new JsApiPay();
                        jsApiPay.openid = openid;
                        jsApiPay.total_fee = total_fee;

                        //JSAPI支付预处理
                        WxPayData unifiedOrderResult = jsApiPay.GetUnifiedOrderResult(body, attach, tradeNo);//这个函数是我修改的，下载的微信SDK里一些参数他是写死的，我改成传参了。
                        string wxJsApiParam = jsApiPay.GetJsApiParameters();//获取H5调起JS API参数
                        return Content(js.Serialize(new { code = 1, msg = "操作成功", data = wxJsApiParam }));
                    }
                    else
                    {
                        return Content(js.Serialize(new { code = -2, msg = "用户不存在" }));//用户不存在
                    }
                }
                else
                {
                    return Content(js.Serialize(new { code = -1, msg = "参数异常" }));//参数异常
                }
            }
            catch (Exception ex)
            {
                Log.Error("WX/GeneralWXPayPara", ex.Message);
                return Content(js.Serialize(new { code = -3, msg = "系统异常：" + ex.Message }));//系统异常
            }
        }

        /// <summary>
        /// 微信支付异步通知
        /// http://www.xxx.com/WX/WXNotify
        /// </summary>
        /// <returns></returns>
        [AcceptVerbs("POST", "GET")]
        public ContentResult WXNotify()
        {
            try
            {
                WxPayData res = new WxPayData();
                ResultNotify resultNotify = new ResultNotify();
                string xmlStr = resultNotify.ProcessNotify();//获取通知结果
                WxPayData notifyData = resultNotify.notifyData;
                //判断通知合法
                if (resultNotify.Success)
                {
                    string return_code = ""; //SUCCESS/FAIL，这个要进行判断的，因为微信可能会传null过来。
                    if (notifyData.GetValue("return_code") != null)
                    {
                        return_code = notifyData.GetValue("return_code").ToString();
                    }
                    string return_msg = "";
                    if (notifyData.GetValue("return_msg") != null)
                    {
                        return_msg = notifyData.GetValue("return_msg").ToString();
                    }
                    //判断是否通信成功
                    if (return_code == "SUCCESS")
                    {
                        string result_code = "";
                        if (notifyData.GetValue("result_code") != null)
                        {
                            result_code = notifyData.GetValue("result_code").ToString();
                        }

                        string err_code_des = "";
                        if (notifyData.GetValue("err_code_des") != null)
                        {
                            err_code_des = notifyData.GetValue("err_code_des").ToString();
                        }
                        //判断支付成功
                        if (result_code == "SUCCESS")
                        {
                            string openid = notifyData.GetValue("openid").ToString();
                            string out_trade_no = notifyData.GetValue("out_trade_no").ToString();
                            int total_fee = Convert.ToInt32(notifyData.GetValue("total_fee").ToString());
                            int attach = Convert.ToInt32(notifyData.GetValue("attach").ToString());//附加字符串（商品ID）
                            Models.UserInfo userinfo = UserInfoBLL.GetEntityByOpenID(openid);
                            int no1 = 0;
                            //生成订单信息
                            Models.TradeInfo model = new Models.TradeInfo(); 
                            model.CreateDate = DateTime.Now;
                            model.Description = "";
                            if (userinfo != null)
                            {
                                model.Description = "userid:" + userinfo.ID + ";openid:" + openid + ";NickName:" + userinfo.nickname + ";Mobile:" + userinfo.Mobile + ";";
                            }
                            model.PayMethod = Convert.ToInt32(Common.EnumHelper.TradePayMethod.微信);
                            
                                model.TradeTypeID = 1;
                                model.ProID = attach;
                                model.Title = "购买商品";
                            
                            model.TotalFee = Convert.ToDouble(total_fee) / 100;//把金额的单位 分 转化为 圆
                            model.TradeNo = out_trade_no;
                            model.TradeStatus = "SUCCESS";
                            model.UserID = userinfo.ID;
                            no1 = TradeInfoBLL.Append(model);
                            Log.Error("WX/WXNotify", "添加订单");

                            if (no1 > 0)
                            {
                                
                                    res.SetValue("return_code", "SUCCESS");
                                    res.SetValue("return_msg", "OK");
                                    return Content(res.ToXml());
                                
                            }
                        }
                        else
                        {
                            Log.Error("WX", "支付失败 : " + err_code_des);
                            res.SetValue("return_code", "FAIL");
                            res.SetValue("return_msg", "支付失败：" + err_code_des);
                            return Content(res.ToXml());
                        }
                    }
                    else
                    {
                        Log.Error("WX", "通信失败 : " + return_msg);
                        res.SetValue("return_code", "FAIL");
                        res.SetValue("return_msg", "通信失败：" + return_msg);
                        return Content(res.ToXml());
                    }
                }

                res.SetValue("return_code", "FAIL");
                res.SetValue("return_msg", "逻辑处理异常");
                return Content(res.ToXml());
            }
            catch (Exception ex)
            {
                WxPayData res = new WxPayData();
                res.SetValue("return_code", "FAIL");
                res.SetValue("return_msg", "系统处理异常");
                Log.Error("WX", "WXNotify Exception : " + ex.ToString());
                return Content(res.ToXml());
            }
        }

 发起微信支付的js：

function BuyProduct(openid, proid) {
    callpay(openid, 2, proid);
}
function BuyVip(openid) {
    callpay(openid, 1, 0);
}
//调用微信JS api 支付
function jsApiCall(openid, TradeTypeID, ProID) {
    //生成支付参数
    $.ajax({
        type: "POST",
        dataType: "json",
        url: "/WX/GeneralWXPayPara",
        data: { openid: openid, TradeTypeID: TradeTypeID, ProID: ProID },
        success: function (result) {
            if (result.code == 1) {
                //进入支付
                var jd = $.parseJSON(result.data);//注意转化成json数据
                WeixinJSBridge.invoke('getBrandWCPayRequest', jd, function (res) {
                    //alert(JSON.stringify(res));//提示支付结果
                    if (res.err_msg == "get_brand_wcpay_request:ok") {
                        alert("支付成功");
                    }
                    else {
                        alert("支付失败");
                    }
                });
            }
            else {
                alert(result.msg);
            }
        }
    });
}

function callpay(openid, TradeTypeID, ProID) {
    if (typeof WeixinJSBridge == "undefined") {
        if (document.addEventListener) {
            document.addEventListener('WeixinJSBridgeReady', jsApiCall, false);
        }
        else if (document.attachEvent) {
            document.attachEvent('WeixinJSBridgeReady', jsApiCall);
            document.attachEvent('onWeixinJSBridgeReady', jsApiCall);
        }
    }
    else {
        jsApiCall(openid, TradeTypeID, ProID);
    }
}