在这里，我已经为如何从头开始获取 RegID 和通知编写了几个步骤
- 在 Google Cloud 上创建/注册应用
- 使用开发设置 Cloud SDK
- 为 GCM 配置项目
- 获取设备注册 ID
- 发送推送通知
- 接收推送通知
您可以在下面的 URL 链接中找到完整的教程
Android 推送通知入门：最新的 Google Cloud Messaging (GCM) - 分步完整教程
获取注册 ID（推送通知的设备令牌）的代码片段。
为 GCM 配置项目
更新 AndroidManifest 文件
为了在我们的项目中启用 GCM，我们需要在清单文件中添加一些权限转到 AndroidManifest.xml 并添加以下代码添加权限
<uses-permission android:name="android.permission.INTERNET”/>
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name=“.permission.RECEIVE" />
<uses-permission android:name=“<your_package_name_here>.permission.C2D_MESSAGE" />
<permission android:name=“<your_package_name_here>.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
添加 GCM 广播接收器声明
在您的应用程序标签中添加 GCM 广播接收器声明
<application
<receiver
android:name=".GcmBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.SEND" ]]>
<intent-filter]]>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="" />
</intent-filter]]>
</receiver]]>
<application/>
添加 GCM 服务声明
<application
<service android:name=".GcmIntentService" />
<application/>
获取注册 ID（推送通知的设备令牌）
现在转到您的启动/启动活动
添加常量和类变量
private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
public static final String EXTRA_MESSAGE = "message";
public static final String PROPERTY_REG_ID = "registration_id";
private static final String PROPERTY_APP_VERSION = "appVersion";
private final static String TAG = "LaunchActivity";
protected String SENDER_ID = "Your_sender_id";
private GoogleCloudMessaging gcm =null;
private String regid = null;
private Context context= null;
更新 OnCreate 和 OnResume 方法
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_launch);
context = getApplicationContext();
if (checkPlayServices())
{
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(context);
if (regid.isEmpty())
{
registerInBackground();
}
else
{
Log.d(TAG, "No valid Google Play Services APK found.");
}
}
}
@Override protected void onResume()
{
super.onResume(); checkPlayServices();
}
# Implement GCM Required methods (Add below methods in LaunchActivity)
private boolean checkPlayServices() {
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS) {
if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
GooglePlayServicesUtil.getErrorDialog(resultCode, this,
PLAY_SERVICES_RESOLUTION_REQUEST).show();
} else {
Log.d(TAG, "This device is not supported - Google Play Services.");
finish();
}
return false;
}
return true;
}
private String getRegistrationId(Context context)
{
final SharedPreferences prefs = getGCMPreferences(context);
String registrationId = prefs.getString(PROPERTY_REG_ID, "");
if (registrationId.isEmpty()) {
Log.d(TAG, "Registration ID not found.");
return "";
}
int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE);
int currentVersion = getAppVersion(context);
if (registeredVersion != currentVersion) {
Log.d(TAG, "App version changed.");
return "";
}
return registrationId;
}
private SharedPreferences getGCMPreferences(Context context)
{
return getSharedPreferences(LaunchActivity.class.getSimpleName(),
Context.MODE_PRIVATE);
}
private static int getAppVersion(Context context)
{
try
{
PackageInfo packageInfo = context.getPackageManager()
.getPackageInfo(context.getPackageName(), 0);
return packageInfo.versionCode;
}
catch (NameNotFoundException e)
{
throw new RuntimeException("Could not get package name: " + e);
}
}
private void registerInBackground()
{ new AsyncTask() {
Override
protected Object doInBackground(Object... params)
{
String msg = "";
try
{
if (gcm == null)
{
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(SENDER_ID); Log.d(TAG, "########################################");
Log.d(TAG, "Current Device's Registration ID is: "+msg);
}
catch (IOException ex)
{
msg = "Error :" + ex.getMessage();
}
return null;
} protected void onPostExecute(Object result)
{ //to do here };
}.execute(null, null, null);
}
注意：请存储 REGISTRATION_KEY，将 PN 消息发送到 GCM 很重要，也请保留在我的，这对于所有设备都是唯一的，通过使用这个只有 GCM 会发送推送通知。
接收推送通知
添加 GCM 广播接收器类
由于我们已经在 Manifest 文件中声明了“GcmBroadcastReceiver.java”，所以让我们以这种方式创建此类更新接收器类代码
public class GcmBroadcastReceiver extends WakefulBroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent)
{ ComponentName comp = new ComponentName(context.getPackageName(),
GcmIntentService.class.getName()); startWakefulService(context, (intent.setComponent(comp)));
setResultCode(Activity.RESULT_OK);
Toast.makeText(context, “wow!! received new push notification", Toast.LENGTH_LONG).show();
}
}
添加 GCM 服务类
由于我们已经在 Manifest 文件中声明了“GcmBroadcastReceiver.java”，所以让我们以这种方式创建此类更新接收器类代码
public class GcmIntentService extends IntentService
{ public static final int NOTIFICATION_ID = 1; private NotificationManager mNotificationManager; private final static String TAG = "GcmIntentService"; public GcmIntentService() {
super("GcmIntentService");
} @Override
protected void onHandleIntent(Intent intent) {
Bundle extras = intent.getExtras();
Log.d(TAG, "Notification Data Json :" + extras.getString("message"));
GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
String messageType = gcm.getMessageType(intent); if (!extras.isEmpty()) { if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR
.equals(messageType)) {
sendNotification("Send error: " + extras.toString());
} else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED
.equals(messageType)) {
sendNotification("Deleted messages on server: "
+ extras.toString()); // If it's a regular GCM message, do some work.
} else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE
.equals(messageType)) {
// This loop represents the service doing some work.
for (int i = 0; i < 5; i++) {
Log.d(TAG," Working... " + (i + 1) + "/5 @ "
+ SystemClock.elapsedRealtime()); try {
Thread.sleep(5000);
} catch (InterruptedException e) {
}
}
Log.i(TAG, "Completed work @ " + SystemClock.elapsedRealtime());
sendNotification(extras.getString("message"));
}
} // Release the wake lock provided by the WakefulBroadcastReceiver.
GcmBroadcastReceiver.completeWakefulIntent(intent);
} // Put the message into a notification and post it.
// This is just one simple example of what you might choose to do with
// a GCM message.
private void sendNotification(String msg) { mNotificationManager = (NotificationManager) this
.getSystemService(Context.NOTIFICATION_SERVICE);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, LaunchActivity.class), 0);
NotificationCompat.Builder mBuilder = new NotificationCompat.Builder( this)
.setSmallIcon(R.drawable.icon)
.setContentTitle("Ocutag Snap")
.setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
.setContentText(msg)
.setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE);
mBuilder.setContentIntent(contentIntent); mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
}
}