虽然我试着对这个问题对方回答，就不能得到解决。 发件人ID是正确的，权限添加，API密钥是真实的。

Although I try other answer about this problem, it can't be solved. Sender ID is correct, permissions are added, API key is true.

我用这篇文章来创建项目： http://developer.android.com/guide/google/gcm/gs.html#server-app

I use this post for creating the project: http://developer.android.com/guide/google/gcm/gs.html#server-app

    GCMRegistrar.checkDevice(this);
    GCMRegistrar.checkManifest(this);
    String regId = GCMRegistrar.getRegistrationId(this);
    if (regId.equals("")) {
      GCMRegistrar.register(this, SENDER_ID);
      regId = GCMRegistrar.getRegistrationId(this);
    } else {
      Log.v(TAG, "Already registered");
    }
    String did = getDeviceID();

返回空字符串。

it returns empty string.

推荐答案

你有 GCMIntentService 中定义的 的正确，在你的应用程序的根包？

Do you have GCMIntentService defined correctly at the root package of your app?

<receiver android:name="com.google.android.gcm.GCMBroadcastReceiver" android:permission="com.google.android.c2dm.permission.SEND" >

  <intent-filter>
    <action android:name="com.google.android.c2dm.intent.RECEIVE" />
    <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
    <category android:name="my_app_package" />
  </intent-filter>
</receiver>

请确保my_app_package等同于您的应用程序的主包，或者你的ID将返回一个空字符串。

Make sure that "my_app_package" is identical to the main package of your app, or your id will return an empty string.

另请注意，

    GCMRegistrar.register(this, "...");

是异步的。因此，调用 GCMRegistrar.getRegistrationId（本）后是不可靠的，所以你应该避免它。

is asynchronous. Therefore, calling GCMRegistrar.getRegistrationId(this) immediately after that is not reliable, so you should avoid it.

该ID将通过广播回调到达您的 GCMIntentService ，作为注册过程的一部分。从那里，你可以比存储GCM键您想要的位置，并用它在应用程序（通常是服务器）上的其他部分。

The id will arrive via broadcast callback to your GCMIntentService, as a part of the registration procedure. from there you can than store the gcm key anywhere you like, and use it in other parts of the application (usually on the server).