沙盒测试第二笔付款失败Paypal集成asp.net mvc

Question

I am trying to integrate Paypal in my .net mvc project. I create an app and add a code in the web.config and in my controller (To see the code see below). I am able to make a single transaction on a new account But when Ever I called another transaction it returned Transaction failed : The remote server returned an error: (400) Bad Request.

Here below is my web.config code

    <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=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
    <section name="paypal" type="PayPal.SDKConfigHandler, PayPal" />
  </configSections>
  <!-- PayPal SDK settings -->
  <paypal>
    <settings>
      <add name="mode" value="sandbox" />
      <!--<add name="clientId" value="AfLQXEBebCzqXtXyPYW987x5Zg75PXpTgYACmv8i9pMaWiMCN0U-FIkKPngd3WQ4YK9J-_gE1ZfMiQlb" />
      <add name="clientSecret" value="EFNJZjqrmGkAY-W4-NmCRq-DgkEmCgRteDY_v4aBf6TTU55ZwARMj0399UfFZ5T7iExAtoqq3tdOuyd" />-->
      <add name="clientId" value="AQ3-ATuhAujxd7-Y5BVOKw8fdlIt5KlDul1d0OIJ4hQavS0smxF0Np_MfO6tZXAcuYqklG33yycQnNvj" />
      <add name="clientSecret" value="EA77LpQNkL8U6xH96A2VZTKXjdthToF8yFsw4SKRfGmY5iHMxTv_yxJXMxBHCeXVnNFF_EO5UOeDjq1Q" />
    </settings>
  </paypal>

and following are my controller which call paypal api

public ActionResult PaymentWithPaypal(string Cancel = null)
    {
        //getting the apiContext  
        APIContext apiContext = PaypalConfiguration.GetAPIContext();
        ////try
        ////{
            //A resource representing a Payer that funds a payment Payment Method as paypal  
            //Payer Id will be returned when payment proceeds or click to pay  
            string payerId = Request.Params["PayerID"];
            if (string.IsNullOrEmpty(payerId))
            {
                //this section will be executed first because PayerID doesn't exist  
                //it is returned by the create function call of the payment class  
                // Creating a payment  
                // baseURL is the url on which paypal sendsback the data.  
                string baseURI = Request.Url.Scheme + "://" + Request.Url.Authority + "/Home/PaymentWithPayPal?";
                //here we are generating guid for storing the paymentID received in session  
                //which will be used in the payment execution  
                var guid = Convert.ToString((new Random()).Next(100000));
                //CreatePayment function gives us the payment approval url  
                //on which payer is redirected for paypal account payment  
                var createdPayment = this.CreatePayment(apiContext, baseURI + "guid=" + guid);
                //get links returned from paypal in response to Create function call  
                var links = createdPayment.links.GetEnumerator();
                string paypalRedirectUrl = null;
                while (links.MoveNext())
                {
                    Links lnk = links.Current;
                    if (lnk.rel.ToLower().Trim().Equals("approval_url"))
                    {
                        //saving the payapalredirect URL to which user will be redirected for payment  
                        paypalRedirectUrl = lnk.href;
                    }
                }
                // saving the paymentID in the key guid  
                Session.Add(guid, createdPayment.id);
                return Redirect(paypalRedirectUrl);
            }
            else
            {
                // This function exectues after receving all parameters for the payment  
                var guid = Request.Params["guid"];
                var executedPayment = ExecutePayment(apiContext, payerId, Session[guid] as string);
                //If executed payment failed then we will show payment failure message to user  
                if (executedPayment.state.ToLower() != "approved")
                {
                    return View("FailureView");
                }
            }
        //}
        catch (Exception ex)
        {
            return View("FailureView");
        }
        //on successful payment, show success page to user.  
        return View("SuccessView");
    }

    private Payment ExecutePayment(APIContext apiContext, string payerId, string paymentId)
    {
        var paymentExecution = new PaymentExecution()
        {
            payer_id = payerId
        };
        this.payment = new Payment()
        {
            id = paymentId
        };
        var a = payment.Execute(apiContext, paymentExecution);
        return a;
    }
    private Payment CreatePayment(APIContext apiContext, string redirectUrl)
    {
        //create itemlist and add item objects to it  
        var itemList = new ItemList()
        {
            items = new List<Item>()
        };
        //Adding Item Details like name, currency, price etc  
        itemList.items.Add(new Item()
        {
            name = "Item Name comes here",
            currency = "USD",
            price = "10",
            quantity = "1",
            sku = "sku"
        });
        var payer = new Payer()
        {
            payment_method = "paypal"
        };
        // Configure Redirect Urls here with RedirectUrls object  
        var redirUrls = new RedirectUrls()
        {
            cancel_url = redirectUrl + "&Cancel=true",
            return_url = redirectUrl
        };
        // Adding Tax, shipping and Subtotal details  
        var details = new Details()
        {
            tax = "1",
            shipping = "1",
            subtotal = "10"
        };
        //Final amount with details  
        var amount = new Amount()
        {
            currency = "USD",
            total = "12", // Total must be equal to sum of tax, shipping and subtotal.  
            details = details
        };
        var transactionList = new List<Transaction>();
        // Adding description about the transaction  
        transactionList.Add(new Transaction()
        {
            description = "Transaction description",
            invoice_number = "your generated invoice number", //Generate an Invoice No  
            amount = amount,
            item_list = itemList
        });
        this.payment = new Payment()
        {
            intent = "sale",
            payer = payer,
            transactions = transactionList,
            redirect_urls = redirUrls
        };
        // Create a payment using a APIContext  
        return this.payment.Create(apiContext);
    }

Answer 1

use Below Code to resolve the issue.

public Payment CreatePayment(APIContext apiContext, string redirectUrl)
{
    //create itemlist and add item objects to it
    var itemList = new ItemList() { items = new List<Item>() };

    //Adding Item Details like name, currency, price etc
    itemList.items.Add(new Item()
    {
        name = "Item Name comes here",
        currency = "USD",
        price = "4",
        quantity = "1",
        sku = "sku"
    });

    var payer = new Payer() { payment_method = "paypal" };

    // Configure Redirect Urls here with RedirectUrls object
    var redirUrls = new RedirectUrls()
    {
        cancel_url = redirectUrl + "&Cancel=true",
        return_url = redirectUrl
    };

    // Adding Tax, shipping and Subtotal details
    var details = new Details()
    {
        tax = "1",
        shipping = "1",
        subtotal = "4",
        shipping_discount = "-1"
    };

    //Final amount with details
    var amount = new Amount()
    {
        currency = "USD",
        total = "5", // Total must be equal to sum of tax, shipping and subtotal.
        details = details
    };

    var transactionList = new List<Transaction>();
    // Adding description about the transaction
    transactionList.Add(new Transaction()
    {
        description = "Transaction description",
        invoice_number = Convert.ToString((new Random()).Next(100000)), 
        amount = amount,
        item_list = itemList
    });


    this.payment = new Payment()
    {
        intent = "sale",
        payer = payer,
        transactions = transactionList,
        redirect_urls = redirUrls
    };

    // Create a payment using a APIContext
    return this.payment.Create(apiContext);
}

Regards Omkar.