Zardify Zardify - 1 year ago 153
ASP.NET (C#) Question

PayPal .NET SDK - new Payment() - throws NullReference exception

I'm trying to implement PayPal through their .NET SDK. (C#)
I'm working with ASP.NET (Web Forms).
Whenever I try to create (simply by constructor) a new Payment object, I get a NullReferenceException with absolutely NO detail in it...

Here's the exception:

System.NullReferenceException was unhandled by user code
Message=Object reference not set to an instance of an object.
at <SolutionName>.Classes.MFPal.Checkout(List`1 cartItems) in C:\<SolutionName>\<FolderName>\Classes\MFPal.cs:line 46
at <SolutionName>.Pages.Private.ShoppingCart.btnPPCheckout_Click(Object sender, EventArgs e) in C:\<SolutionName>\<FolderName>\Pages\Private\ShoppingCart.aspx.cs:line 164
at System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e)
at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

InnerException is null by the way.

I've already decoupled the code to the bare minimum, I've tested first with a filled ItemList, now I'm just using an empty one. Now I'm also using "0" for every price, but my first tests were made with correct numbers. At first I used simply;

Payment.Create(apiContext, new Payment() { ... });

But I couldn't identify the NullReference, so now the code looks like this:

var apiContext = new APIContext(Config.PayPalAccessToken);
apiContext.Config = ConfigManager.Instance.GetProperties();
apiContext.HTTPHeaders = new Dictionary<string, string>();

Payment pym = new Payment() {
intent = "sale",
redirect_urls = {
return_url = "http://<DomainName>/home",
cancel_url = "http://<DomainName>/home"
payer = { payment_method = "paypal" },
transactions = new List<Transaction>() {
new Transaction() {
amount = {
currency = "USD",
total = "0",
details = new Details() {
tax = "0",
shipping = "0",
subtotal = "0"
item_list = new ItemList() { items = new List<Item>() },
description = "asd",
invoice_number = "1111111"

Is anyone experiencing similar problems? Am I missing something? A needed property maybe? When I debug, I can't find anything null.

Thank you in advance!

Answer Source

I've found the problem. Went through it line by line until I realized it. I forgot (and Visual Studio liked the idea) to leave out:

new Amount() {...}

Constructor from the line:

amount = {...}

I'm sorry for the seemingly pointless post. Maybe someone will eventually have the same mistake.

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