.net core 支付宝，微信支付 三

支付回调：

获取HttpRequest的body内容，之前使用Request.Form有时候数据请求不到（可能是跟.net core 版本有关？）

 var s = HttpRequest.Body;
                int count;
                var buffer = new byte[1024];
                var builder = new StringBuilder();
                while ((count = s.Read(buffer, 0, 1024)) > 0)
                {
                    builder.Append(Encoding.UTF8.GetString(buffer, 0, count));
                }
                s.Flush();
                s.Dispose();

获取到回调内容，接下来按照支付平台来处理。

支付宝回调：

var alipayReturnData = builder.ToString().Split('&').ToDictionary(a => a.Split('=')[0], a => System.Net.WebUtility.UrlDecode(a.Split('=')[1]));

将返回的数据分割开来，decode后填装到字典里后，获取sign值等相关数据后，剔除sign及signType，将剩余值排序后调用密钥验签后判断结果

//request 接收的字符串含有urlencode，这里需要decode一下
                var alipayReturnData = builder.ToString().Split('&').ToDictionary(a => a.Split('=')[0], a => System.Net.WebUtility.UrlDecode(a.Split('=')[1]));
                //获取sign
                var sign = alipayReturnData["sign"];
                //去除sign及signtype
                alipayReturnData.Remove("sign");
                alipayReturnData.Remove("sign_type");
                //获取支付宝订单号及商户交易订单号
                var tradeNo = alipayReturnData["trade_no"];
                var tradeIds = alipayReturnData["out_trade_no"];

                var dic = alipayReturnData.ToDictionary(d => d.Key, d => d.Value);

                var preSign = BuildData.BuildParamStr(dic);
                //验签
                var result = GenerateRsaAssist.VerifySign(preSign, AliPayConfig.AliPublicKey, sign, SignType.Rsa2);

排序代码：

public static string BuildParamStr(Dictionary<string, string> param)
        {
            if (param == null || param.Count == 0)
            {
                return "";
            }
            var ascDic = param.OrderBy(o => o.Key).ToDictionary(o => o.Key, p => p.Value);
            var sb = new StringBuilder();
            foreach (var item in ascDic)
            {
                if (!string.IsNullOrEmpty(item.Value))
                {
                    sb.Append(item.Key).Append("=").Append(item.Value).Append("&");
                }
            }
            return sb.ToString().Substring(0, sb.ToString().Length - 1);
        }

获取结果后剩下的就交给业务代码处理了。

微信回调：

创建WxPayData类，并将HttpRequest的body获取到的stringbuilder内容转换成xml

var notifyData = new WxPayData();
notifyData.FromXml(builder.ToString());

检查支付结果中transaction_id是否存在

  if (!notifyData.IsSet("transaction_id"))
            {
                //若transaction_id不存在，则立即返回结果给微信支付后台
                var res = new WxPayData();
                res.SetValue("return_code", "FAIL");
                res.SetValue("return_msg", "支付结果中微信订单号不存在");
                return new WeChatNotifyRequest { IsVerify = false, PayNo = "", TradeIds = "", PayTime = "", Sign = "", Content = res.ToXml() };
            }

查询订单，判断订单真实性

 var transactionId = notifyData.GetValue("transaction_id").ToString();
            var tradeIds = notifyData.GetValue("out_trade_no").ToString();
            var payTime = notifyData.GetValue("time_end").ToString();

            //查询订单，判断订单真实性
            if (!await QueryOrder(transactionId))
            {
                //若订单查询失败，则立即返回结果给微信支付后台
                var res = new WxPayData();
                res.SetValue("return_code", "FAIL");
                res.SetValue("return_msg", "订单查询失败");
                return new WeChatNotifyRequest { IsVerify = false, PayNo = "", TradeIds = "", PayTime = "", Sign = "", Content = res.ToXml() };
            }
            //查询订单成功
            else
            {
                var res = new WxPayData();
                res.SetValue("return_code", "SUCCESS");
                res.SetValue("return_msg", "OK");
                return new WeChatNotifyRequest { IsVerify = true, PayNo = transactionId, TradeIds = tradeIds, PayTime = payTime, Sign = "", Content = res.ToXml() };
            }

注意的是如果回调成功，要返回值给支付平台，不然平台没有收到结果会一直调用回调内容

支付宝返回：success 或者fail

微信返回xml格式，

<xml>

<return_code><![CDATA[SUCCESS]]></return_code>
  <return_msg><![CDATA[OK]]></return_msg>
</xml>