V3 微信支付-预支付C#

首先不得不吐槽下腾讯，升级微信支付为毛不兼容V2版本呢？V2算是白研究了。

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V3预支付文档几个坑，不知道你们有没有中招

1. 商户号 mch_id 是 String(32) 微信支付分配的商户号   其实是邮件的“微信支付商户号（接口文档中的商户号MCHID）” ，我一直都以为是商户号。
2. 预支付提交的xml节点值都必须带有<![CDATA[]]>，如果根据文档开发只带部分。那么你就开心了，一直都是sign签名错误。

回到正文，以下为实现代码

public class PaymentHandler : RequestHandler
    {

        public PaymentHandler(HttpContext context)
            : base(context, WX_V3_CONFIG.config.PartnerKey)
        {

        }

        /// <summary>
        /// 获取预支付订单号
        /// </summary>
        /// <returns></returns>
        public string GetUnifiedOrder(string body, string openid, string trade_type)
        {

            base.setParameter("appid", WX_V3_CONFIG.config.AppID);
            base.setParameter("mch_id", WX_V3_CONFIG.config.MCHID);
            base.setParameter("nonce_str", TenpayUtil.getNoncestr());
            base.setParameter("body", body);
            base.setParameter("out_trade_no", TenpayUtil.getOrderNo());
            base.setParameter("total_fee", "");
            base.setParameter("spbill_create_ip", "192.168.1.1");//base.httpContext.Request.UserHostAddress);
            base.setParameter("notify_url", "www.111.com");
            base.setParameter("trade_type", "JSAPI");
            base.setParameter("openid", openid);
            base.createSign();

            string s = HttpHelper.OpenReadWithHttps("https://api.mch.weixin.qq.com/pay/unifiedorder", base.parseXML());//post请求

            return "";
        }
    }

RequestHandler帮助类

/// <summary>
    /// RequestHandler 的摘要说明。
    /// </summary>
    public class RequestHandler
    {

        public RequestHandler(HttpContext httpContext, string key)
        {
            parameters = new Hashtable();
            this.key = key;
            this.httpContext = httpContext;

        }
        /**  密钥 */
        private string key;

        protected HttpContext httpContext;

        /** 请求的参数 */
        protected Hashtable parameters;

        /** debug信息 */
        private string debugInfo;

        /** 初始化函数 */
        public virtual void init()
        {
        }
        /** 获取debug信息 */
        public String getDebugInfo()
        {
            return debugInfo;
        }
        /** 获取密钥 */
        public String getKey()
        {
            return key;
        }

        /** 设置密钥 */
        public void setKey(string key)
        {
            this.key = key;
        }

        /** 设置参数值 */
        public void setParameter(string parameter, string parameterValue)
        {
            if (parameter != null && parameter != "")
            {
                if (parameters.Contains(parameter))
                {
                    parameters.Remove(parameter);
                }

                parameters.Add(parameter, parameterValue);
            }
        }

        /** 获取参数值 */
        public string getParameter(string parameter)
        {
            string s = (string)parameters[parameter];
            return (null == s) ? "" : s;
        }

        //获取package带参数的签名包
        public string getRequestURL()
        {
            this.createSign();
            StringBuilder sb = new StringBuilder();
            ArrayList akeys = new ArrayList(parameters.Keys);
            akeys.Sort();
            foreach (string k in akeys)
            {
                string v = (string)parameters[k];
                if (null != v && "key".CompareTo(k) != )
                {
                    sb.Append(k + "=" + TenpayUtil.UrlEncode(v, getCharset()) + "&");
                }
            }

            //去掉最后一个&
            if (sb.Length > )
            {
                sb.Remove(sb.Length - , );
            }

            return sb.ToString();

        }

        //创建md5摘要,规则是:按参数名称a-z排序,遇到空值的参数不参加签名。

        protected virtual void createSign()
        {
            StringBuilder sb = new StringBuilder();

            ArrayList akeys = new ArrayList(parameters.Keys);
            akeys.Sort();

            foreach (string k in akeys)
            {
                string v = (string)parameters[k];
                if (null != v && "".CompareTo(v) !=
                    && "sign".CompareTo(k) !=  && "key".CompareTo(k) != )
                {
                    sb.Append(k + "=" + v + "&");
                }
            }

            sb.Append("key=" + this.getKey());
            string sign = MD5Util.GetMD5(sb.ToString(), getCharset()).ToUpper();

            this.setParameter("sign", sign);

            //debug信息
            this.setDebugInfo(sb.ToString() + " => sign:" + sign);
        }

        //创建package签名
        public virtual string createMd5Sign()
        {
            StringBuilder sb = new StringBuilder();
            ArrayList akeys = new ArrayList(parameters.Keys);
            akeys.Sort();

            foreach (string k in akeys)
            {
                string v = (string)parameters[k];
                if (null != v && "".CompareTo(v) !=
                    && "sign".CompareTo(k) !=  && "".CompareTo(v) != )
                {
                    sb.Append(k + "=" + v + "&");
                }
            }
            string sign = MD5Util.GetMD5(sb.ToString(), getCharset()).ToLower();

            this.setParameter("sign", sign);
            return sign;
        }

        //创建sha1签名
        public string createSHA1Sign()
        {
            StringBuilder sb = new StringBuilder();
            ArrayList akeys = new ArrayList(parameters.Keys);
            akeys.Sort();

            foreach (string k in akeys)
            {
                string v = (string)parameters[k];
                if (null != v && "".CompareTo(v) !=
                       && "sign".CompareTo(k) !=  && "key".CompareTo(k) != )
                {
                    if (sb.Length == )
                    {
                        sb.Append(k + "=" + v);
                    }
                    else
                    {
                        sb.Append("&" + k + "=" + v);
                    }
                }
            }
            string paySign = SHA1Util.getSha1(sb.ToString()).ToString().ToLower();

            //debug信息
            this.setDebugInfo(sb.ToString() + " => sign:" + paySign);
            return paySign;
        }

        //输出XML
        public string parseXML()
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("<xml>");
            foreach (string k in parameters.Keys)
            {
                string v = (string)parameters[k];
                if (Regex.IsMatch(v, @"^[0-9.]$"))
                {

                    sb.Append("<" + k + ">" + v + "</" + k + ">");
                }
                else
                {
                    sb.Append("<" + k + "><![CDATA[" + v + "]]></" + k + ">");
                }

            }
            sb.Append("</xml>");
            return sb.ToString();
        }

        /** 设置debug信息 */
        public void setDebugInfo(String debugInfo)
        {
            this.debugInfo = debugInfo;
        }

        public Hashtable getAllParameters()
        {
            return this.parameters;
        }

        protected virtual string getCharset()
        {
            return this.httpContext.Request.ContentEncoding.BodyName;
        }
    }