C# 实现微信退款及对帐
目录
需求
基础准备
关键代码
操作界面
编辑
退款订单类及方法
退款功能实现
对帐
支付商家后台相关要点
实时交易帐单查询
精确交易帐单查询
小结
需求
在招聘报名系统里，考务费支付是其中一个环节，支付方式很多种，比如银联、微信、支付宝等等。本次我们以微信支付进行举例，在考生注册账号、编写简历、报名职位、被初审核通过等一系列基础的条件的具备下，可以进入支付考务费的环节（笔试费用），我们会为其生成一个支付二维码，考生支付后（无论成功与否），都会记录其支付结果状态。
在实际的应用中，对于支付成功的考生，我们会遇到实现退款的需求，只要包括如下场景：
1、根据政策规定，某些符合全部或部分退款条件的考生。
2、其它未知原因，重复支付订单的考生。
3、其它不可抗力，需求进行退款的考生。
基础准备
在实现功能前，做为企业，我们需要申请一个微信服务号，并成为微信支付商家。
1、申请服务号
申请成功后会获得到 AppId 和 AppSecret 用于后续开发，如关联支付商户、网页授权登录等。
具体指引请参照微信公众平台首页：https://mp.weixin.qq.com/cgi-bin/loginpage
2、成为微信支付商家
申请成功后会获得 Mchid 和 paySignKey 用于微信支付、退款等，请在商家后台务必关联申请的公众号。
具体指引请参照微信支付平台首页：https://pay.weixin.qq.com/index.php/core/home/login
上述两个平台申请成功后，请登录微信支付商家平台，进行如下图操作：
在产品中心、AppID帐号管理、关联 AppID（即申请的服务号）
另外一个重要配置是支付目录，我们写的支付程序需要在这里设置，如下图：
关键代码
操作界面
界面上会显示最近一笔的微信订单支付情况，包括订单号、交费时间、交费金额、退款金额。其中退款金额不能大于成功交费金额，否则会返回失败。另外，还可以显示微信交易跟踪日志列表信息，如果订单号、交易价格、openid、返回信息、交易状态等。
示例界面如下：
退款订单类及方法
实现微信退款，需要在支付商家平台申请退款证书，证书文件保存到自定义的目录中，在退款时指定路径。
退款示例代码如下：
const string RefundOrderUrl = "https://api.mch.weixin.qq.com/secapi/pay/refund"; //退款申请API地址
const string RefundQueryUrl = "https://api.mch.weixin.qq.com/pay/refundquery"; //退款查询API地址
//退款订单明细类
public class RefundOrderDetail
{
/// <summary>
/// 返回状态码，SUCCESS/FAIL 此字段是通信标识，非交易标识，交易是否成功需要查看trade_state来判断
/// </summary>
public string return_code = "";
/// <summary>
/// 返回信息返回信息，如非空，为错误原因 签名失败 参数格式校验错误
/// </summary>
public string return_msg = "";
/// <summary>
/// 业务结果,SUCCESS/FAIL
/// </summary>
public string result_code = "";
/// <summary>
/// 错误代码
/// </summary>
public string err_code = "";
/// <summary>
/// 错误代码描述
/// </summary>
public string err_code_des = "";
/// <summary>
/// 公众号ID(微信分配的公众账号 ID)
/// </summary>
public string appid = "";
/// <summary>
/// 商户号(微信支付分配的商户号)
/// </summary>
public string mch_id = "";
/// <summary>
/// 微信支付分配的终端设备号
/// </summary>
public string device_info = "";
/// <summary>
/// 随机字符串，不长于32位
/// </summary>
public string nonce_str = "";
/// <summary>
/// 签名
/// </summary>
public string sign = "";
/// <summary>
/// 微信支付订单号
/// </summary>
public string transaction_id = "";
/// <summary>
/// 商户系统的订单号，与请求一致。
/// </summary>
public string out_trade_no = "";
public string out_refund_no = "";
public string refund_id = "";
public string refund_fee = "";
public string settlement_refund_fee = "";
/// <summary>
/// 订单总金额，单位为分
/// </summary>
public string total_fee = "";
/// </summary>
public string settlement_total_fee = "";
public string fee_type = "";
public string cash_fee = "";
public string cash_fee_type = "";
public string cash_refund_fee = "";
public string coupon_type_0 = "";
public string coupon_refund_fee = "";
public string coupon_refund_fee_0 = "";
public string coupon_refund_count = "";
public string coupon_refund_id_0 = "";
}
//退款订单类
public class RefundOrder
{
/// <summary>
/// 公众号ID(微信分配的公众账号 ID)
/// </summary>
public string appid = "";
/// <summary>
/// 商户号(微信支付分配的商户号)
/// </summary>
public string mch_id = "";
/// <summary>
/// 微信支付分配的终端设备号
/// </summary>
public string device_info = "";
/// <summary>
/// 随机字符串，不长于 32 位
/// </summary>
public string nonce_str = "";
/// <summary>
/// 签名
public string sign = "";
public string sign_type = "";
/// <summary>
/// 商户系统内部的订单号,32个字符内、可包含字母,确保在商户系统唯一,详细说明
/// </summary>
public string transaction_id = "";
public string out_trade_no = "";
public string out_refund_no = "";
/// <summary>
/// 订单总金额，单位为分，不能带小数点
/// </summary>
public int total_fee = 0;
public int refund_fee = 0;
public string refund_fee_type = "";
public string op_user_id = "";
/// <summary>
public string refund_account = "";
/// <summary>
}
//查询对帐订单类
public class QueryOrder
{
/// <summary>
/// 公共号ID(微信分配的公众账号 ID)
/// </summary>
public string appid = "";
/// <summary>
/// 商户号(微信支付分配的商户号)
/// </summary>
public string mch_id = "";
/// <summary>
/// 微信订单号，优先使用
/// </summary>
public string transaction_id = "";
/// <summary>
/// 商户系统内部订单号
/// </summary>
public string out_trade_no = "";
/// <summary>
/// 随机字符串，不长于 32 位
/// </summary>
public string nonce_str = "";
/// <summary>
/// 签名，参与签名参数：appid，mch_id，transaction_id，out_trade_no，nonce_str，key
/// </summary>
public string sign = "";
}
//申请退款方法，返回退款订单明细类
//参数refundorder为退款订单类, key 为支付签名KEY,cert为证书地址,password 为证书密码
public RefundOrderDetail getRefundOrderDetail(RefundOrder refundorder, string key,string cert,string password)
{
string post_data = getRefundOrderXml(refundorder, key);
string request_data = PostXmlAndCertToUrl(RefundOrderUrl, post_data,cert,password);
RefundOrderDetail orderdetail = new RefundOrderDetail();
SortedDictionary<string, string> requestXML = GetInfoFromXml(request_data);
foreach (KeyValuePair<string, string> k in requestXML)
{
switch (k.Key)
{
case "retuen_code":
orderdetail.result_code = k.Value;
break;
case "return_msg":
orderdetail.return_msg = k.Value;
break;
case "result_code":
orderdetail.result_code = k.Value;
break;
case "err_code":
orderdetail.err_code = k.Value;
break;
case "err_code_des":
orderdetail.err_code_des = k.Value;
break;
case "appid":
orderdetail.appid = k.Value;
break;
case "mch_id":
orderdetail.mch_id = k.Value;
break;
case "device_info":
orderdetail.device_info = k.Value;
break;
case "nonce_str":
orderdetail.nonce_str = k.Value;
break;
case "sign":
orderdetail.sign = k.Value;
break;
case "transaction_id":
orderdetail.transaction_id = k.Value;
break;
case "out_trade_no":
orderdetail.out_trade_no = k.Value;
break;
case "out_refund_no":
orderdetail.out_refund_no = k.Value;
break;
case "refund_id":
orderdetail.refund_id = k.Value;
break;
case "refund_fee":
orderdetail.refund_fee = k.Value;
break;
case "total_fee":
orderdetail.total_fee = k.Value;
break;
case "settlement_refund_fee":
orderdetail.settlement_refund_fee = k.Value;
break;
case "settlement_total_fee":
orderdetail.settlement_total_fee = k.Value;
break;
case "fee_type":
orderdetail.fee_type = k.Value;
break;
case "cash_fee":
orderdetail.cash_fee = k.Value;
break;
case "cash_fee_type ":
orderdetail.cash_fee_type = k.Value;
break;
case "cash_refund_fee":
orderdetail.cash_refund_fee = k.Value;
break;
case "coupon_type_0":
orderdetail.coupon_type_0 = k.Value;
break;
case "coupon_refund_fee":
orderdetail.coupon_refund_fee = k.Value;
break;
case "coupon_refund_fee_0":
orderdetail.coupon_refund_fee_0 = k.Value;
break;
case "coupon_refund_count":
orderdetail.coupon_refund_count = k.Value;
break;
case "coupon_refund_id_0":
orderdetail.coupon_refund_id_0 = k.Value;
break;
default:
break;
}
}
return orderdetail;
}
protected string getRefundOrderXml(RefundOrder refundorder, string key)
{
string return_string = string.Empty;
SortedDictionary<string, string> sParams = new SortedDictionary<string, string>();
sParams.Add("appid", refundorder.appid);
sParams.Add("mch_id", refundorder.mch_id);
// sParams.Add("transaction_id", refundorder.transaction_id);
sParams.Add("out_trade_no", refundorder.out_trade_no);
sParams.Add("nonce_str", refundorder.nonce_str);
sParams.Add("out_refund_no", refundorder.out_refund_no);
sParams.Add("total_fee", refundorder.total_fee.ToString());
sParams.Add("refund_fee", refundorder.refund_fee.ToString());
sParams.Add("op_user_id", refundorder.op_user_id);
refundorder.sign = getsign(sParams, key);
sParams.Add("sign", refundorder.sign);
//拼接成XML请求数据
StringBuilder sbPay = new StringBuilder();
foreach (KeyValuePair<string, string> k in sParams)
{
if (k.Key == "attach" || k.Key == "body" || k.Key == "sign")
{
sbPay.Append("<" + k.Key + "><![CDATA[" + k.Value + "]]></" + k.Key + ">");
}
else
{
sbPay.Append("<" + k.Key + ">" + k.Value + "</" + k.Key + ">");
}
}
return_string = string.Format("<xml>{0}</xml>", sbPay.ToString().TrimEnd(','));
return return_string;
}
public string PostXmlAndCertToUrl(string url, string postData,string cert,string password)
{
string resp = string.Empty;
ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
//调用证书
System.Security.Cryptography.X509Certificates.X509Certificate2 cer = new System.Security.Cryptography.X509Certificates.X509Certificate2(cert, password, System.Security.Cryptography.X509Certificates.X509KeyStorageFlags.PersistKeySet | System.Security.Cryptography.X509Certificates.X509KeyStorageFlags.MachineKeySet);
HttpWebRequest webrequest = (HttpWebRequest)HttpWebRequest.Create(url);
webrequest.ClientCertificates.Add(cer);
webrequest.Method = "post";
webrequest.ContentType = "application/x-www-form-urlencoded";
webrequest.ContentLength = postData.Length;
//webrequest.ContentType = "text/xml";
//byte[] data = System.Text.Encoding.UTF8.GetBytes(postData);
//webrequest.ContentLength = data.Length;
HttpWebResponse response = null;
try
{
StreamWriter swRequestWriter = new StreamWriter(webrequest.GetRequestStream());
swRequestWriter.Write(postData);
if (swRequestWriter != null)
swRequestWriter.Close();
response = (HttpWebResponse)webrequest.GetResponse();
using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
{
resp = reader.ReadToEnd();
}
}
catch (Exception exp)
{
throw exp;
}
finally
{
if (response != null)
response.Close();
}
return resp;
}
public string getNoncestr()
{
Random random = new Random();
return GetMD5(random.Next(1000).ToString(), "GBK").ToLower().Replace("s", "S");
}
退款功能实现
假设点击退款按钮事件
protected void Button_Click(object sender, EventArgs e)
{
string appId = “”； //服务号的appId
string paySignKey = “”； //申请的支付签名KEY;
string mch_id = “”; //申请的支付商户ID
string OrderID = ""; //支付订单号
string OrderAmount = (Convert.ToInt32((float.Parse(Amount.Text) * 100))).ToString(); //订单支付金额，Amount.Text 支付金额
string RefundOrderAmount = (Convert.ToInt32((float.Parse(Amount.Text) * 100))).ToString(); //退款金额（Amount.Text）这里表示全额退款
string RefundOrderID = Guid.NewGuid().ToString().Replace("-", ""); //生成退款订单号
//创建退款订单
RefundOrder order = new RefundOrder();
order.appid = appId;
order.mch_id = mch_id;
order.out_trade_no = OrderID;
order.nonce_str = tenpay.getNoncestr();
order.out_refund_no = RefundOrderID;
order.total_fee = int.Parse(OrderAmount);
order.refund_fee = int.Parse(RefundOrderAmount);
order.op_user_id = mch_id;
string cert = “d:\\apiclient_cert.p12"; //退款证书路径
//私钥（在安装证书时设置）
string password =""; //证书密码
//创建订单明细类，调用getRefundOrderDetail方法进行退款
RefundOrderDetail orderdetail = getRefundOrderDetail(order, paySignKey, cert, password);
string rv = ("退款订单号:" + RefundOrderID + "<br>");
try
{
rv += ("退款金额:" + (double.Parse(orderdetail.total_fee) / 100).ToString() + "<br>");
}
catch (Exception eee)
{
rv += ("退款金额:<br>");
}
rv += ("<b>交易状态: " + (orderdetail.result_code == "SUCCESS" ? "退款申请成功" : "退款申请失败") + "(" + orderdetail.result_code + ")" + "</b><br>");
rv += ("可能的错误描述:" + orderdetail.err_code_des);
}对帐
退款申请成功后，仅为申请状态，需要通过查询退款情况以确定是否完成，该功能可以在考生方进行实现，考生可随时查询自己的对帐情况。
以下是参考代码，该代码可实现支付与退款的查询：
protected void queryOrder(object sender, EventArgs e)
{
string OrderID =”“; //订单号
string paytype = ”“； //查询类型，支付消费或退款
string appId = ""; //服务号 appid
string paySignKey = ""; //支付签名key
string mch_id = ""; //支付商户号
if (paytype == "消费")
{
try
{
string openid = ”“;
QueryOrder order = new QueryOrder();
order.appid = appId;
order.mch_id = mch_id;
order.out_trade_no = OrderID;
order.nonce_str = getNoncestr();
OrderDetail orderdetail = getOrderDetail(order, paySignKey);
string rv = ("订单号:" + OrderID + "<br>");
rv += ("付款人ID比对识别:" + (openid == orderdetail.openid ? "成功" : "失败") + "<br>");
rv += ("交易金额:" + (double.Parse(orderdetail.total_fee) / 100).ToString() + "<br>");
rv += ("<b>交易状态: " + (orderdetail.trade_state == "SUCCESS" ? "成功" : "失败") + "(" + orderdetail.trade_state + ")" + "</b><br>");
rv += ("支付交易时间:" + (orderdetail.time_end != "" && orderdetail.time_end.Length == 14 ? orderdetail.time_end.Substring(0, 4) + "-" + orderdetail.time_end.Substring(4, 2) + "-" + orderdetail.time_end.Substring(6, 2) + " " + orderdetail.time_end.Substring(8, 2) + ":" + orderdetail.time_end.Substring(10, 2) + ":" + orderdetail.time_end.Substring(12, 2) : "") + "<br>");
}
catch (Exception ex)
{
return;
}
}
else if (paytype == "退款")
{
try
{
RefundOrder order = new RefundOrder();
order.appid = appId;
order.mch_id = mch_id;
order.out_trade_no = OrderID;
order.nonce_str = getNoncestr();
RefundOrderDetail orderdetail = getRefundQueryOrderDetail(order, paySignKey);
string rv = ("<b>交易状态: " + (orderdetail.result_code == "SUCCESS" ? "成功" : "失败") + "(" + orderdetail.result_code + ")" + "</b><br>");
rv += ("其它说明:" + orderdetail.err_code_des);
}
catch (Exception ex)
{
}
}
}
支付商家后台相关要点
实时交易帐单查询
登录后台后，该操作可以进行实时交易的帐单对帐功能，以备在争议的时候进行查询，基本操作如下图：
点击交易中心、交易订单、批量订单查询、查询即可下载EXCEL格式的订单。
精确交易帐单查询
登录后台后，可查询精确交易帐单，该帐单每天10：00更新前一天的数据交易，我们可以进行CSV格式的下载，操作如下图：
点击交易中心、交易帐单、打包下载即可，请注意图中圈注的提示。
小结
以上提供的代码仅供参考，在实际的应用中，我们还可以根据业务需要编写其它功能，如下载微信官方对帐单，导入到应用系统中，与业务数据进行对帐，以排查争议数据；查询订单结果状态以更新业务争议状态信息等。
以上就是自己的一些分享，时间仓促，不妥之处还请大家批评指正！