PayPal IPN集成（快速结帐-Razor / C＃）

Question

I am currently trying to integrate PayPal with my site, and everything's gone well - up to the point where we do our IPN checking thing.

It gets right down to the if/elseif/else block and that's where it ends. It outputs a message, that reads:

"Invalid status. form_charset=UTF8"

Here is the code that I have.

@using System.Collections.Generic
@using System.Text
@using System.Web
@using System.Web.UI
@using System.Web.UI.HtmlControls
@using System.Web.UI.WebControls
@using System.ComponentModel

@{
    Layout = "~/_SiteLayout.cshtml";
    Page.Title = "Checkout | SSSSS";

    string postUrl = "https://www.paypal.com/cgi-bin/webscr";
    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(postUrl);

    //Set values for the request back
    req.Method = "POST";
    req.ContentType = "application/x-www-form-urlencoded";
    byte[] param = Request.BinaryRead(HttpContext.Current.Request.ContentLength);
    string strRequest = System.Text.Encoding.UTF8.GetString(param);
    string ipnPost = strRequest;
    strRequest += "&cmd=_notify-validate";
    req.ContentLength = strRequest.Length;

    //for proxy
    //WebProxy proxy = new WebProxy(new Uri("http://url:port#"));
    //req.Proxy = proxy;

    //Send the request to PayPal and get the response
    StreamWriter streamOut = new StreamWriter(req.GetRequestStream(), 
                             System.Text.Encoding.UTF8);
    streamOut.Write(strRequest);

    streamOut.Close();

    StreamReader streamIn = new StreamReader(req.GetResponse().GetResponseStream());
    string strResponse = streamIn.ReadToEnd();
    streamIn.Close();

    /*/ logging ipn messages... be sure that you give write
    // permission to process executing this code
    string logPathDir = ResolveUrl("Messages");
    string logPath = string.Format("{0}\\{1}.txt", 
                     Server.MapPath(logPathDir), DateTime.Now.Ticks);
    File.WriteAllText(logPath, ipnPost);
    /*/

}
@if (strResponse == "VERIFIED")
{
    /*---------------- WILL DO OTHER CHECKS LATER    ------------------*/
    //check the payment_status is Completed
    <p>status is verified</p>
    //check that txn_id has not been previously processed
    //check that receiver_email is your Primary PayPal email
    //check that payment_amount/payment_currency are correct
    //process payment
}
else if (strResponse == "INVALID")
{
    //log for manual investigation
    <p>status is invalid.</p>

<p>@ipnPost</p>
}
else
{
    //log response/ipn data for manual investigation
    <p>status is invalid.</p>
<p>@ipnPost</p>
}

I'm at a complete loss as to why this isn't working as expected; I would appreciate any help at all.

Answer 1

I am not fluent in Razor, but here is how I do my asp.net webforms one. I believe this was from another website(or most of it anyway), and I sadly don't remember where. So credit is not mine for the basics of this code.

string strLive = "https://www.paypal.com/cgi-bin/webscr";
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(strLive); 
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
byte[] param = Request.BinaryRead(HttpContext.Current.Request.ContentLength);
string strRequest = Encoding.ASCII.GetString(param);
strRequest += "&cmd=_notify-validate";
req.ContentLength = strRequest.Length;

StreamWriter streamOut = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII);
streamOut.Write(strRequest);
streamOut.Close();
StreamReader streamIn = new StreamReader(req.GetResponse().GetResponseStream());
string strResponse = streamIn.ReadToEnd();
streamIn.Close();

NameValueCollection ppDetails = HttpUtility.ParseQueryString(strRequest);
if (strResponse == "VERIFIED"){
if (ppDetails["payment_status"] == "Completed"){
//yay, give them goodies
} else if (strResponse == "INVALID"){
//log IP and possibly block them from your web services if malicious
} else {
//log response/ipn data for manual investigation
}
}

The main difference seems to be that you use UTF8, and the code I have that works uses ASCII. I also added the 'ppDetails' part to give you an idea of how to handle the variables.

Hope it helps. Took me forever to figure out Paypal IPN, and once I did, I felt so silly.