Question

我想从我的ASP.NET WEB API Post方法向我的简单Android应用程序发送一个小推送通知。以下是我尝试和重新搜索的内容。

我正在使用Google Cloud Messaging Service向应用发送通知。我的应用程序在名称值对中收到它。我还在这里给出了Post Code中可用的Java版服务器代码和我的C＃实现。但我的方法抛出异常＆＃34;出现错误的异常为（15913）：println需要一条消息＆＃34;在Android应用程序中。

服务器部分的工作Java代码如下： -

public void sendmessage2Device(View v,String regisID,String msg1,String msg2) {

    HttpClient client = new DefaultHttpClient();
    HttpPost post = new HttpPost(
            "https://android.googleapis.com/gcm/send");


    try {

        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
        nameValuePairs.add(new BasicNameValuePair("registration_id",regisID));

        nameValuePairs.add(new BasicNameValuePair("data1",msg1));
        nameValuePairs.add(new BasicNameValuePair("data2", msg2));






        post.setHeader("Authorization","key=AIzaSyBB6igK9sYYBTSIly6SRUHFVexeOa_7FuM");
        post.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");




        post.setEntity(new UrlEncodedFormEntity(nameValuePairs));
        HttpResponse response = client.execute(post);
        InputStreamReader inputst = new InputStreamReader(response.getEntity().getContent());
        BufferedReader rd = new BufferedReader(inputst);


        String line = "";
        while ((line = rd.readLine()) != null) {
            Log.e("HttpResponse", line);


                String s = line.substring(0);
                Log.i("GCM response",s);
                //Toast.makeText(v.getContext(), s, Toast.LENGTH_LONG).show();


        }

    } catch (IOException e) {
        e.printStackTrace();
    }

类似于ASP.NET WEB API中的My C＃代码如下......

public String Post([FromBody]TransactionDetails value)
    {
        try
        {
            WebClient toGCM = new WebClient();
            toGCM.Headers.Add("ContentType:");
            toGCM.Headers["ContentType"] = "application/x-www-form-urlencoded; charset=UTF-8";
            //HttpWebRequest toGCM = (HttpWebRequest)WebRequest.Create("https://android.googleapis.com/gcm/send");
            //toGCM.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
            toGCM.Headers.Add("Accept:");
            toGCM.Headers["Accept"]= "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36";
            //toGCM.Accept = "application/json, text/javascript, */*; q=0.01";
            toGCM.Headers.Add("UserAgent:") ;
            toGCM.Headers["UserAgent"]= "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.114 Safari/537.36";
            toGCM.Headers.Add("Authorization:");
            toGCM.Headers["Authorization"] = "key=AIzaSyCoxjeOGi_1ss2TeShDcoYbNcPU9_0J_TY";
            //String DatatoClient = "ToAccountNumber=" + value.ToAccountNumber + "&Amount=" + value.Amount;
            NameValueCollection postFieldNameValue = new NameValueCollection();
            postFieldNameValue.Add("registration_id", "APA91bHzO52-3TsEIMV3RXi45ICIo9HOe1ospPl3gRYwAAw59ATHvadGPZN86heHOQJNU8syju-yD9UQqSgkZOqllGi5AoSPMRRuw3RYhgApflr0abLoAh2GWFQCZgToG_aM0rOg0lBV8osz6ZMtP1JBF1S9_DiWiqKRT5WL6qFz4PqyE0jCHsE");
            postFieldNameValue.Add("Account", value.ToAccountNumber.ToString());
            postFieldNameValue.Add("Amount", value.Amount.ToString());

            byte[] responseArray = toGCM.UploadValues("https://android.googleapis.com/gcm/send", postFieldNameValue);
            String S=Encoding.ASCII.GetString(responseArray);
            return S;
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception Occured in Post Method on Web Server as:{0}", e.Message);
            return e.Message;
        }
    }

在Android APP中，我有以下适用于Receiver的LOC ...

public void onReceive(Context context, Intent intent) {
    try {
        String action = intent.getAction();
        if (action.equals("com.google.android.c2dm.intent.REGISTRATION"))
        {
            String registrationId = intent.getStringExtra("registration_id");
            Log.i("Received the Registration Id as ",registrationId);
            String error = intent.getStringExtra("error");
            String unregistered = intent.getStringExtra("unregistered"); 
        }
        else if (action.equals("com.google.android.c2dm.intent.RECEIVE")) 
        {
            Log.i("In the RECEIVE Method ",intent.getStringExtra("Account"));
            String Account = intent.getStringExtra("Account");
            String Amount = intent.getStringExtra("Amount");
            Log.i("Received Account as ",Account);
            Log.i("Received Amount as  ",Amount);
        }
    }
    catch(Exception e)
    {
        Log.i("Exception Occured with Error as ",e.getMessage());
    }
    finally
    {

    }

我是Android开发的新手，这是我的第一个Helloworld Android应用程序。任何人都可以告诉我，我做错了什么，以及为什么抛出异常以及如何纠正它？

Answer 1

经过一些实质性研究后发现了这个问题。我假设Log.i（）在内部使用println将消息打印到LOG。由于GCM没有推送我的客户端代码正在寻找的任何数据，它会引发异常。保持这一点，我得到了PUSH通知的工作，这是我学到的，因为它可能对其他有相同问题的人有用。

GCM使用JSON接收并将通知推送到设备
GCM收到的JSON格式如下

{data： {帐户：您的电话号码，金额：您的金额 }， registration_ids：ID1，ID2，ID3 ...] }

因此，我在ASP.NET服务器端构建了上述JSON格式，并将Http请求传递给GCM Server，其中包含Authorization标头。在我的接收方，我在我的案例中提取了所需的数据（账户和金额）并相应地显示给用户。

PFB我的ASP.NET服务器端和客户端接收器的代码。

服务器端： -

public String Post([FromBody]TransactionDetails value, HttpRequestMessage receivedReq)
    {
        try
        {
            var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://android.googleapis.com/gcm/send");
            httpWebRequest.ContentType = "application/json; charset=UTF-8";
            httpWebRequest.Method = "POST";
            httpWebRequest.Headers.Add("Authorization", "key=AIzaSyBs_eh4nNVaJl3FjQ_ZC72ZZ6uQ2F8r8W4");
            String result = "";
            String yourresp = "<html><head><title>Response from Server</title></head><body>";
            using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
            {
                string json = "{\"data\":" +"{\"Amount\":"+value.Amount+","+
                                "\"Account\":"+value.ToAccountNumber+"}"+","+
                                "\"registration_ids\":[" + "\""+value.RegID +"\"]}";


                streamWriter.Write(json);
                streamWriter.Flush();
                streamWriter.Close();

                var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
                using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
                {
                     result = streamReader.ReadToEnd();
                }
            }
            DialogResult result1 = MessageBox.Show("Server sent the details to your phone, Check and Confirm to Continue or Not", "Important Information",MessageBoxButtons.YesNo);
            if (result1.ToString().Contains("Yes"))
            {
                WriteAccountNumber(value.ToAccountNumber, value.Amount);
                yourresp += "<h1>The Transaction was Successful</h1>";

            }
            else
            {
                yourresp += "<h1>The Transaction was NOT Successful</h1>";
            }
            yourresp += "</body></html>";
            return yourresp;
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception Occured in Post Method on Web Server as:{0}", e.Message);
            return e.Message;
        }
    }

Android App中的客户端如下： -

else if (action.equals("com.google.android.c2dm.intent.RECEIVE")) 
        {
            //Log.i("Message Received","Before Scheme");

            String Account=intent.getStringExtra("Account");
            String Amount=intent.getStringExtra("Amount");
            Toast.makeText(context, "Your Transaction Details Received by the Server are...\n\nAccount="+Account+"\nAmount="+Amount, Toast.LENGTH_LONG).show();
            Log.i("Account=",Account);
            Log.i("Amount=",Amount);
        }

所以，现在我只想知道如何在警报或任何类型的对话框中显示收到的通知，并带有确定按钮。任何人都可以帮我上课，如何在我的应用程序中使用它来显示给用户？如果应用程序未激活，它可以显示在Notifcation栏中，否则需要弹出一个OK按钮。

谢谢，

从ASP.NET发送推送通知到Android应用程序

1 个答案: