asp.net mvc4 运用 paypal sdk实现支付

1.https://developer.paypal.com/ 注册账号，并且申请一个app，获得 client id，secret等数据

 

2.点击页面中"Sandbox Account"按钮，创建至少两个账号(一个收钱用，一个付钱用)，paypal中sandbox是测试环境。live是上线后的环境。

3.下载paypal sdk for .net，https://github.com/paypal/rest-api-sdk-dotnet

4.新建一个解决方案(本例为mvc4 web程序:Paypalsample)，根据需求选择适合的SDK文件,或者还可以通过NuGet(如果你的vs带有此功能)的方式来添加SDK，以下是vs2012的添加过程

5.OK，paypal SDK加进来了，接下来要对web.config文件进行配置,参考地址：https://github.com/paypal/sdk-core-dotnet/wiki/SDK-Configuration-Parameters#list-of-configuration-parameters

 <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
    <section name="paypal" type="PayPal.Manager.SDKConfigHandler, PayPalCoreSDK"/>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
  </configSections>
  <!-- PayPal SDK config -->
  <paypal>
    <settings>
      <!--<add name="endpoint" value="https://api.sandbox.paypal.com"/>-->
      <add name="mode" value="sandbox" /><!--or set value "live" -->
      <add name="connectionTimeout" value=""/>
      <add name="requestRetries" value=""/>
      <add name="ClientID" value="AU0OwhDpDM05PVDfyhm3qpgdXfIc0hNv2O_HaaXbHhA_BvZgwD6sbVloijMW"/>
      <add name="ClientSecret" value="EM3wHxDSvX3QTRKxPMZKHmBtjxYQtscVzzimbnD7FWx7aE0kJ6H5srmvtyZ0"/>
    </settings>
  </paypal>

  <log4net>
    <appender name="FileAppender" type="log4net.Appender.FileAppender">
      <file value="RestApiSDKUnitTestLog.log"/>
      <appendToFile value="true"/>
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] %message%newline"/>
      </layout>
    </appender>
    <root>
      <level value="DEBUG"/>
      <appender-ref ref="FileAppender"/>
    </root>
  </log4net>

6.接下来就是调用Paypal API实现支付，上文中提到下载SDK，其中有sample的例子，可以参考看看，里面实现了大部分常用的api，本例只实现支付的功能。

   a.(视图)页面1部分:

@{
    ViewBag.Title = "Index";
}

<a href="@Url.Action("Payment")">Payment with Paypal account</a>

b.页面2部分：

@{
    ViewBag.Title = "Payment";
}

<h1>Payment Status: @ViewBag.Status</h1>

c.(controller)页面2后台代码部分：

public ActionResult Payment()
        {
            //get access token
            string accessToken = null;
            string clientID = ConfigManager.Instance.GetProperties()["ClientID"];
            string clientSecret = ConfigManager.Instance.GetProperties()["ClientSecret"];
            OAuthTokenCredential TokenCredential = new OAuthTokenCredential(clientID, clientSecret);
            accessToken = TokenCredential.GetAccessToken();

            Payment pymnt = null;

            // ## ExecutePayment
            if (Request.Params["PayerID"] != null)
            {
                pymnt = new Payment();
                if (Request.Params["guid"] != null)
                {
                    pymnt.id = (string)Session[Request.Params["guid"]];
                    try
                    {
                        PaymentExecution pymntExecution = new PaymentExecution();
                        pymntExecution.payer_id = Request.Params["PayerID"];

                        Payment executedPayment = pymnt.Execute(accessToken, pymntExecution);
                        ViewBag.Status = executedPayment.state;
                    }
                    catch (PayPal.Exception.PayPalException ex)
                    {

                    }
                }
            }

            // ## Creating Payment
            else
            {
                // ###Items
                // Items within a transaction.
                Item item = new Item();
                item.name = "笔记本电脑";
                item.currency = "USD";
                item.price = "";
                item.quantity = "";
                item.sku = "台";

                List<Item> itms = new List<Item>();
                itms.Add(item);
                ItemList itemList = new ItemList();
                itemList.items = itms;

                // ###Payer
                // A resource representing a Payer that funds a payment
                // Payment Method
                // as `paypal`
                Payer payr = new Payer();
                payr.payment_method = "paypal";
                Random rndm = new Random();
                var guid = Convert.ToString(rndm.Next());

                string baseURI = Request.Url.Scheme + "://" + Request.Url.Authority + "/Paypal/";

                // # Redirect URLS
                RedirectUrls redirUrls = new RedirectUrls();
                redirUrls.cancel_url = baseURI + "guid=" + guid;
                redirUrls.return_url = baseURI + "Payment?guid=" + guid;

                // ###Details
                // Let's you specify details of a payment amount.
                Details details = new Details();
                details.tax = "";
                details.shipping = "";
                details.subtotal = "";

                // ###Amount
                // Let's you specify a payment amount.
                Amount amnt = new Amount();
                amnt.currency = "USD";
                // Total must be equal to sum of shipping, tax and subtotal.
                amnt.total = "";
                amnt.details = details;

                // ###Transaction
                // A transaction defines the contract of a
                // payment - what is the payment for and who
                // is fulfilling it.
                List<Transaction> transactionList = new List<Transaction>();
                Transaction tran = new Transaction();
                tran.description = "Transaction description.";
                tran.amount = amnt;
                tran.item_list = itemList;
                // The Payment creation API requires a list of
                // Transaction; add the created `Transaction`
                // to a List
                transactionList.Add(tran);

                // ###Payment
                // A Payment Resource; create one using
                // the above types and intent as `sale` or `authorize`
                pymnt = new Payment();
                pymnt.intent = "sale";
                pymnt.payer = payr;
                pymnt.transactions = transactionList;
                pymnt.redirect_urls = redirUrls;

                try
                {
                    string approvalUrl = "";
                    Payment createdPayment = pymnt.Create(accessToken);

                    var links = createdPayment.links.GetEnumerator();

                    while (links.MoveNext())
                    {
                        Links lnk = links.Current;
                        if (lnk.rel.ToLower().Trim().Equals("approval_url"))
                        {
                            approvalUrl = lnk.href;
                        }
                    }
                    Session.Add(guid, createdPayment.id);
                    if (!string.IsNullOrEmpty(approvalUrl))
                        return Redirect(approvalUrl);
                }
                catch (PayPal.Exception.PayPalException ex)
                {
                }
            }
            return View();
        }

c.注意return_url的正确性，总钱数和分项目的钱数要对到，total=subtotal+shipping+tax.其中有些字段非必须，详细参考官方api：https://developer.paypal.com/webapps/developer/docs/api/#create-a-payment

7.运行调试

付款成功后payment status字段的值会有所变化，此支付方式分成两个步骤，第一是create payment，创建一个支付清单，然后用户输入用户名和密码进行支付确认，然后执行ExecutePayment方法进行支付。支付成功后再去看看付款的账号的余额和收款账号的余额。

以同样的方式去查看收款账号是否收到钱，整个过程结束。