public ActionResult IPN()
{
var order = new Order(); // this is something I have defined in
order to save the order in the database
// Receive IPN request from PayPal and parse all the variables
returned
var formVals = new Dictionary<string, string>();
formVals.Add("cmd", "_notify-synch"); //notify-synch_notify
validate
formVals.Add("at", "this is a long token found in Buyers
account"); // this has to be adjusted
formVals.Add("tx", Request["tx"]);
// if you want to use the PayPal sandbox change this from false to
true
string response = GetPayPalResponse(formVals, false);
if (response.Contains("SUCCESS"))
{
string transactionID = GetPDTValue(response, "txn_id"); //
txn_id //d
string sAmountPaid = GetPDTValue(response,"mc_gross"); // d
string deviceID = GetPDTValue(response, "custom"); // d
string payerEmail = GetPDTValue(response,"payer_email"); // d
string Item = GetPDTValue(response,"item_name");
//validate the order
Decimal amountPaid = 0;
Decimal.TryParse(sAmountPaid,
System.Globalization.NumberStyles.Number,
System.Globalization.CultureInfo.InvariantCulture, out amountPaid);
if (amountPaid == 9 ) // you might want to have a bigger than
or equal to sign here!
{
if (orders.Count(d => d.PayPalOrderRef == transactionID) <
1)
{
//if the transactionID is not found in the database,
add it
//then, add the additional features to the user
account
}
else
{
//if we are here, the user must have already used the
transaction ID for an account
//you might want to show the details of the order, but
do not upgrade it!
}
// take the information returned and store this into a
subscription table
// this is where you would update your database with the
details of the tran
//return View();
}
else
{
// let fail - this is the IPN so there is no viewer
// you may want to log something here
order.Comments = "User did not pay the right ammount.";
// since the user did not pay the right amount, we still
want to log that for future reference.
_db.Orders.Add(order); // order is your new Order
_db.SaveChanges();
}
}
else
{
//error
}
return View();
}
string GetPayPalResponse(Dictionary<string, string> formVals, bool
useSandbox)
{
string paypalUrl = useSandbox ?
"https://www.sandbox.paypal.com/cgi-bin/webscr"
: "https://www.paypal.com/cgi-bin/webscr";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(paypalUrl);
// Set values for the request back
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
byte[] param = Request.BinaryRead(Request.ContentLength);
string strRequest = Encoding.ASCII.GetString(param);
StringBuilder sb = new StringBuilder();
sb.Append(strRequest);
foreach (string key in formVals.Keys)
{
sb.AppendFormat("&{0}={1}", key, formVals[key]);
}
strRequest += sb.ToString();
req.ContentLength = strRequest.Length;
//for proxy
//WebProxy proxy = new WebProxy(new Uri("http://urlort#");
//req.Proxy = proxy;
//Send the request to PayPal and get the response
string response = "";
using (StreamWriter streamOut = new
StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII))
{
streamOut.Write(strRequest);
streamOut.Close();
using (StreamReader streamIn = new
StreamReader(req.GetResponse().GetResponseStream()))
{
response = streamIn.ReadToEnd();
}
}
return response;
}
string GetPDTValue(string pdt, string key)
{
string[] keys = pdt.Split('\n');
string thisVal = "";
string thisKey = "";
foreach (string s in keys)
{
string[] bits = s.Split('=');
if (bits.Length > 1)
{
thisVal = bits[1];
thisKey = bits[0];
if (thisKey.Equals(key,
StringComparison.InvariantCultureIgnoreCase))
break;
}
}
return thisVal;
}
