我不断收到21002显示java.lang.NullPointerException从苹果的错误，当我尝试测试我的应用程序内购买在沙箱中。这是我做了什么：

I keep getting 21002 'java.lang.NullPointerException' errors from Apple when I try to test my In-App Purchases in the sandbox. This is what I have done:

设置了应用程序内购买的产品在iTunes Connect。我可以通过StoreKit成功找回它们。 在iTunes Connect中设置的测试用户。 在应用程序启动时，会下载可用的应用程序内购买的产品，我触发应用程序内购买和苹果回应与transactionReceipt，这是我的base64恩code iPhone和发送到我的C＃/ ASP。 NET服务器。 服务器会将接收到的字符串转换成JSON（我想它都与 NewtonSoft.Json 和手动），并发送JSON苹果： Set up the In-App Purchase products in iTunes Connect. I can successfully retrieve them via StoreKit. Set up test user in iTunes Connect. Application starts up, downloads the available In-App Purchase products, I trigger the In-App Purchase and Apple responds with the transactionReceipt, which I base64-encode on the iPhone and send to my C#/ASP.NET server. The server puts the received string into JSON (I tried it both with NewtonSoft.Json and manually) and sends the JSON to Apple:

VAR JSON ={'接收数据：+收据+'};

或

VAR JSON =新JObject（新JProperty（接收数据，收据））的ToString（）;

然后：

var webRequest = System.Net.HttpWebRequest.Create("https://sandbox.itunes.apple.com/verifyReceipt");
webRequest.ContentType = "text/plain";
webRequest.Method = "POST";
byte[] byteArray = Encoding.UTF8.GetBytes(receipt);
webRequest.ContentLength = byteArray.Length;
using (var stream = webRequest.GetRequestStream())
{
    stream.Write(byteArray, 0, byteArray.Length);
    stream.Flush();
}

var resp = webRequest.GetResponse();
if (resp != null)
{
    using (var sr = new System.IO.StreamReader(resp.GetResponseStream()))
    {
        var result = sr.ReadToEnd().Trim();
        var iapResponse = Newtonsoft.Json.JsonConvert.DeserializeObject<AppleIapResponse>(result);
        // always getting '21002' 'java.lang.NullPointerException'
    }
}

我什么都试过：改变的ContentType的JSON格式，编码....

I tried everything: changing the ContentType, the JSON formatting, the encoding....

任何提示？

推荐答案

这是在code一个简单的错误，我写了收据进入后，不是JSON：

It's a simple bug in the code, I was writing the receipt into the POST, not the JSON:

byte[] byteArray = Encoding.UTF8.GetBytes(json);
                                          ^^^^

城墙，从撞我的头好痛..

The wall hurts from banging my head against it..