PayPal REST API .net SDK - 400 Bad Requests

Question

I\'m working in the sandbox and using the PayPal REST .net SDK method Payment.Create with a CreditCard object. When all parameters are valid and using the test CC number from h

Answer 1

Since no one seems to know the answer to this, I dug into the source code of PayPal's .NET SDK for REST API. From this review, it appears that as of the current version, there is no provision for returning the error messages when any 4xx or 5xx HTTP status code is returned by the server. I referenced the answers to this question and have altered the SDK to allow for returning the error response when applicable. Here's the relevant portion of HttpConnection.cs.

catch (WebException ex)
{
    if (ex.Response is HttpWebResponse)
    {
        HttpStatusCode statusCode = ((HttpWebResponse)ex.Response).StatusCode;
        logger.Info("Got " + statusCode.ToString() + " response from server");
        using (WebResponse wResponse = (HttpWebResponse)ex.Response)
        {
            using (Stream data = wResponse.GetResponseStream ())
            {
                string text = new StreamReader (data).ReadToEnd ();
                return text;
            }
        }                           
    }
    if (!RequiresRetry(ex))
    {
        // Server responses in the range of 4xx and 5xx throw a WebException
        throw new ConnectionException("Invalid HTTP response " + ex.Message);
    }                       
}

Of course, this requires changes to the calling function to properly interpret the error response. Since I'm only using the Payment Create API, I took some shortcuts that wouldn't work for general use. However, the basic idea is that I created PaymentError and Detail classes, then altered the Payment.Create and PayPalResource.ConfigureAndExecute methods to populate and pass back a PaymentError object.

---

Three years later and there is some improvement in PayPal's API error response handling. Because of some other issues I had to re-work my application, and rip out the prior code. I've found that you can now trap for a PayPal.Exception.PaymentsException, then deserialize the JSON Response string into a PayPal.Exception.PaymentsError object.

Catch ex As PayPal.Exception.PaymentsException
    Dim tmpPmtErr As PayPal.Exception.PaymentsError = _
        JsonConvert.DeserializeObject(Of PayPal.Exception.PaymentsError)(ex.Response)

Thanks to @lance in the other answer for the heads-up to examine the exceptions more closely. I attempted to use that solution, but could not make it work.

Answer 2

If you are using a globalization outside the US you need to convert your decimals to a InvariantCulture:

order.GetTotal().ToString("N2", CultureInfo.InvariantCulture)