.NET WEB API 对接支付宝支付

转载请注明出处:http://leejunhui.com/2017/02/09/AliPayWithWebAPI/

最近一个项目中需要自己前后台全栈,几经权衡之后,在还是选择了自己最为熟悉的.NET WEB API技术来实现服务器端。可能是由于太久没接触.NET了,在对接支付宝APP支付的时候,遇到了不少坑,废话不多说,直接上代码吧。

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public class AliPayHelper
{
private static string APP_ID = "";
private static string CHARSET = "UTF-8";
/// <summary>
/// 生成RSA签名后的订单字符串
/// </summary>
/// <param name="price"></param>
/// <param name="description"></param>
/// <returns></returns>
public static string createRSASignedOrderString(double price,string description)
{
Dictionary<string, string> orderStringDict = new Dictionary<string, string>();
orderStringDict.Add("app_id", APP_ID);
orderStringDict.Add("method", "alipay.trade.app.pay");
orderStringDict.Add("format", "JSON");
orderStringDict.Add("charset", "utf-8");
orderStringDict.Add("sign_type", "RSA");
orderStringDict.Add("timestamp", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
orderStringDict.Add("version", "1.0");
orderStringDict.Add("notify_url", "");
orderStringDict.Add("biz_content", generateBizContentString(price.ToString(), description));
// 排序拼接成字符串
string orderInfo = AlipaySignature.GetSignContent(orderStringDict);
string orderInfoEncoded = Core.CreateLinkStringUrlencode(orderStringDict, (new System.Text.UTF8Encoding()));
// 签名
string privateKeyPem = GetCurrentPath() + "rsa_private_key.pem";
string signString = AlipaySignature.RSASign(orderInfo, privateKeyPem, null, "RSA");
signString = HttpUtility.UrlEncode(signString, new UTF8Encoding());
// 加上sign
string orderString = orderInfoEncoded + "&sign=" + signString;
// 拼接最终返回给客户端的字符串
return orderString;
}
static String BytesToBase64(Byte[] bytes)
{
try
{
return Convert.ToBase64String(bytes);
}
catch
{
return null;
}
}
/// <summary>
/// 获取私钥的路径
/// </summary>
/// <returns></returns>
private static string GetCurrentPath()
{
string strPath = "/Helper/";
if (HttpContext.Current != null)
{
return HttpContext.Current.Server.MapPath(strPath);
}
else //非web程序引用
{
strPath = strPath.Replace("/", "\\");
if (strPath.StartsWith("\\"))
{
//strPath = strPath.Substring(strPath.IndexOf('\\', 1)).TrimStart('\\');
strPath = strPath.TrimStart('\\');
}
return System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, strPath);
}
}
/// <summary>
/// 生成业务参数
/// </summary>
/// <param name="price"></param>
/// <param name="descripiton"></param>
/// <returns></returns>
private static string generateBizContentString(string price, string descripiton)
{
Dictionary<string, string> bizContent = new Dictionary<string, string>();
bizContent.Add("subject", descripiton);
bizContent.Add("body", descripiton);
bizContent.Add("out_trade_no", generateOrderNumber());
bizContent.Add("timeout_express", "90m");
bizContent.Add("total_amount", price);
bizContent.Add("product_code", "QUICK_MSECURITY_PAY");
string bizContentJsonString = (new System.Web.Script.Serialization.JavaScriptSerializer()).Serialize(bizContent);
return bizContentJsonString;
}
private static string generateOrderNumber()
{
return DateTime.Now.ToString("yyyyMMddHHmmssfff");
}
}

用法如下:

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public async Task<HttpResponseMessage> AliPaySignString(AlipayRequestModel model)
{
var response = new SingleModelResponse<String>() as ISingleModelResponse<String>;
try
{
await Task.Run(() =>
{
string orderString = AliPayHelper.createRSASignedOrderString(Convert.ToDouble(model.price), model.description);
if (null == orderString)
{
response.DidError = true;
response.info = "签名失败";
}
else
{
response.Model = orderString;
response.info = "签名成功";
}
});
}
catch (Exception ex)
{
response.DidError = true;
response.info = ex.InnerException.Message;
}
return response.ToHttpResponse();
}

上面的代码主要干了一件事情,生成签名后的订单字符串返回给app客户端,然后app客户端拿着这个字符串去调用支付宝SDK,发起支付请求。为什么要这么麻烦呢?一切都是为了安全,根据支付宝官方开发平台的解释,把签名的过程放在服务器端是要比放在客户端更为安全的一种策略。
由于网上关于.NET对接支付宝的文章和教程时效性都已经很低了,所以我把项目中的AliPayHelper代码放在这,供大家参考。
github代码地址

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