Google Cloud Messaging示例主線程

Question

我遇到了Google Cloud to Device消息示例的問題。我遵循這裏的說明（https://github.com/GoogleCloudPlatform/gradle-appengine-templates/tree/master/GcmEndpoints），因爲這是我在創建項目時由Android Build給出的說明。根據說明我創建了註冊和接收消息所需的類。該寄存器創建爲AsyncTask，並從我的主應用程序的OnCreate方法調用。我遇到的問題是每次運行時出現IOException：主線程。我試着將代碼更改爲Runnable，但沒有運氣，我只是得到相同的錯誤。我在文檔中讀過的所有內容都表明，我所做的應該是有效的，所以我不明白爲什麼它不行。

下面是顯示錯誤和堆棧跟蹤

10-19 13:04:21.637 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ java.io.IOException: MAIN_THREAD 
10-19 13:04:21.637 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at com.google.android.gms.gcm.GoogleCloudMessaging.register(Unknown Source) 
10-19 13:04:21.647 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at com.hillbilly.kidslauncher.GcmRegistrationAsyncTask.doInBackground(GcmRegistrationAsyncTask.java:75) 
10-19 13:04:21.647 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at com.hillbilly.kidslauncher.MainActivity.onCreate(MainActivity.java:43) 
10-19 13:04:21.657 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.Activity.performCreate(Activity.java:5008) 
10-19 13:04:21.657 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079) 
10-19 13:04:21.667 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023) 
10-19 13:04:21.667 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084) 
10-19 13:04:21.677 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.ActivityThread.access$600(ActivityThread.java:130) 
10-19 13:04:21.677 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195) 
10-19 13:04:21.677 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:99) 
10-19 13:04:21.687 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.os.Looper.loop(Looper.java:137) 
10-19 13:04:21.687 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:4745) 
10-19 13:04:21.697 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at java.lang.reflect.Method.invokeNative(Native Method) 
10-19 13:04:21.697 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at java.lang.reflect.Method.invoke(Method.java:511) 
10-19 13:04:21.707 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 
10-19 13:04:21.707 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
10-19 13:04:21.717 1291-1291/com.hillbilly.kidslauncher W/System.err﹕ at dalvik.system.NativeStart.main(Native Method)

任何幫助極大完全接受了logcat的轉儲。

如這裏要求是相關代碼：

從主活動的onCreate方法：

protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    this.setContentView(R.layout.activity_main); 
    new GcmRegistrationAsyncTask().doInBackground(this); 
} 

那不是你如何在執行後臺任務的註冊類

package com.hillbilly.kidslauncher; 
import android.content.Context; 
import android.os.AsyncTask; 
import android.widget.Toast; 
import com.appspot.kidslauncherparent.registration.Registration; 
import com.google.android.gms.gcm.GoogleCloudMessaging; 
import com.google.api.client.extensions.android.http.AndroidHttp; 
import com.google.api.client.extensions.android.json.AndroidJsonFactory; 
import com.google.api.client.googleapis.services.AbstractGoogleClientRequest; 
import com.google.api.client.googleapis.services.GoogleClientRequestInitializer; 
import java.io.IOException; 
import java.util.logging.Level; 
import java.util.logging.Logger; 
/** 
* Created by craighillbeck on 19/10/2014. 
*/ 
public class GcmRegistrationAsyncTask extends AsyncTask<Context, Void, String> { 
private GoogleCloudMessaging gcm; 
    private Context context; 
    private Registration regService = null; 

    // TODO: change to your own sender ID to Google Developers Console project number, as per instructions above 
    private static final String SENDER_ID = "978823093525"; 

    /** 
    * Override this method to perform a computation on a background thread. The 
    * specified parameters are the parameters passed to {@link #execute} 
    * by the caller of this task. 
    * <p/> 
    * This method can call {@link #publishProgress} to publish updates 
    * on the UI thread. 
    * 
    * @param params The parameters of the task. 
    * 
    * @return A result, defined by the subclass of this task. 
    * 
    * @see #onPreExecute() 
    * @see #onPostExecute 
    * @see #publishProgress 
    */ 
    @Override 
    protected String doInBackground(Context... params) { 
     context = params[0]; 
     if (regService == null) { 
      Registration.Builder builder = new Registration.Builder(
        AndroidHttp.newCompatibleTransport(), 
        new AndroidJsonFactory(), null) 
        // Need setRootUrl and setGoogleClientRequestInitializer only for local testing, 
        // otherwise they can be skipped 
        .setRootUrl("http://10.0.2.2:8080/_ah/api/") 
        .setGoogleClientRequestInitializer(new GoogleClientRequestInitializer() { 
         @Override 
         public void initialize(AbstractGoogleClientRequest<?> abstractGoogleClientRequest) 
           throws IOException { 
          abstractGoogleClientRequest.setDisableGZipContent(true); 
         } 
        }); 
      // end of optional local run code 
      builder.setApplicationName(context.getString(R.string.app_name)); 
      regService = builder.build(); 
     } 



     String msg = ""; 
     try { 
      if (gcm == null) { 
       gcm = GoogleCloudMessaging.getInstance(context); 
      } 
      String regId = gcm.register(SENDER_ID); 
      msg = "Device registered, registration ID=" + regId; 

      // You should send the registration ID to your server over HTTP, 
      // so it can use GCM/HTTP or CCS to send messages to your app. 
      // The request to your server should be authenticated if your app 
      // is using accounts. 
      regService.register(regId).execute(); 

     } catch (IOException ex) { 
      ex.printStackTrace(); 
      msg = "Error: " + ex.getMessage(); 
     } 
     return msg; 
    } 


    /** 
    * <p>Runs on the UI thread after {@link #doInBackground}. The 
    * specified result is the value returned by {@link #doInBackground}.</p> 
    * <p/> 
    * <p>This method won't be invoked if the task was cancelled.</p> 
    * 
    * @param msg The result of the operation computed by {@link #doInBackground}. 
    * 
    * @see #onPreExecute 
    * @see #doInBackground 
    * @see #onCancelled(Object) 
    */ 
    @Override 
    protected void onPostExecute(String msg) { 
     Toast.makeText(context, msg, Toast.LENGTH_LONG).show(); 
     Logger.getLogger("REGISTRATION").log(Level.INFO, msg); 
    } 
} 

Answer 1

的背景。只需調用doInBackGround()方法在同一個（主）線程中執行此方法，這會導致您的執行。

new GcmRegistrationAsyncTask().doInBackground(this); 

正確的做法是：

new GcmRegistrationAsyncTask().execute(null,null,null); 

下面是來自official GCM demo一個例子：

private void registerInBackground() { 
    new AsyncTask<Void, Void, String>() { 
     @Override 
     protected String doInBackground(Void... params) { 
      String msg = ""; 
      try { 
       if (gcm == null) { 
        gcm = GoogleCloudMessaging.getInstance(context); 
       } 
       regid = gcm.register(SENDER_ID); 
       msg = "Device registered, registration ID=" + regid; 

       // You should send the registration ID to your server over HTTP, so it 
       // can use GCM/HTTP or CCS to send messages to your app. 
       sendRegistrationIdToBackend(); 

       // For this demo: we don't need to send it because the device will send 
       // upstream messages to a server that echo back the message using the 
       // 'from' address in the message. 

       // Persist the regID - no need to register again. 
       storeRegistrationId(context, regid); 
      } catch (IOException ex) { 
       msg = "Error :" + ex.getMessage(); 
       // If there is an error, don't just keep trying to register. 
       // Require the user to click a button again, or perform 
       // exponential back-off. 
      } 
      return msg; 
     } 

     @Override 
     protected void onPostExecute(String msg) { 
      mDisplay.append(msg + "\n"); 
     } 
    }.execute(null, null, null); 
}