我正在尝试实施可以通过GCM接收通知的应用。我的问题是，当我向应用程序添加Java时，QML不再加载。相反，它加载Java UI，即使我没有定义一个，所以我得到一个空屏幕。
如果我创建它，Java中的UI确实会显示，但我只想要通知的Java后端而不是其他内容。
有没有人有这方面的经验？
如何使用我的QML UI并仅使用Java进行通知？
Java代码：
/*
* Copyright 2013 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.qtproject.example.notification;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.gcm.GoogleCloudMessaging;
import android.app.Activity;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.pm.PackageManager;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Main UI for the demo app.
*/
public class DemoActivity extends Activity {
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 static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
/**
* Substitute you own sender ID here. This is the project number you got
* from the API Console, as described in "Getting Started."
*/
String SENDER_ID = "lalalala";
/**
* Tag used on log messages.
*/
static final String TAG = "GCM Demo";
TextView mDisplay;
GoogleCloudMessaging gcm;
AtomicInteger msgId = new AtomicInteger();
Context context;
String regid;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.main);
// mDisplay = (TextView) findViewById(R.id.display);
context = getApplicationContext();
// Check device for Play Services APK. If check succeeds, proceed with GCM registration.
if (checkPlayServices()) {
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(context);
if (regid.isEmpty()) {
registerInBackground();
}
} else {
Log.i(TAG, "No valid Google Play Services APK found.");
}
}
@Override
protected void onResume() {
super.onResume();
// Check device for Play Services APK.
checkPlayServices();
}
/**
* Check the device to make sure it has the Google Play Services APK. If
* it doesn't, display a dialog that allows users to download the APK from
* the Google Play Store or enable it in the device's system settings.
*/
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.i(TAG, "This device is not supported.");
finish();
}
return false;
}
return true;
}
/**
* Stores the registration ID and the app versionCode in the application's
* {@code SharedPreferences}.
*
* @param context application's context.
* @param regId registration ID
*/
private void storeRegistrationId(Context context, String regId) {
final SharedPreferences prefs = getGcmPreferences(context);
int appVersion = getAppVersion(context);
Log.i(TAG, "Saving regId on app version " + appVersion);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(PROPERTY_REG_ID, regId);
editor.putInt(PROPERTY_APP_VERSION, appVersion);
editor.commit();
}
/**
* Gets the current registration ID for application on GCM service, if there is one.
* <p>
* If result is empty, the app needs to register.
*
* @return registration ID, or empty string if there is no existing
* registration ID.
*/
private String getRegistrationId(Context context) {
final SharedPreferences prefs = getGcmPreferences(context);
String registrationId = prefs.getString(PROPERTY_REG_ID, "");
if (registrationId.isEmpty()) {
Log.i(TAG, "Registration not found.");
return "";
}
// Check if app was updated; if so, it must clear the registration ID
// since the existing regID is not guaranteed to work with the new
// app version.
int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE);
int currentVersion = getAppVersion(context);
if (registeredVersion != currentVersion) {
Log.i(TAG, "App version changed.");
return "";
}
return registrationId;
}
/**
* Registers the application with GCM servers asynchronously.
* <p>
* Stores the registration ID and the app versionCode in the application's
* shared preferences.
*/
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);
}
// Send an upstream message.
// public void onClick(final View view) {
// if (view == findViewById(R.id.send)) {
// new AsyncTask<Void, Void, String>() {
// @Override
// protected String doInBackground(Void... params) {
// String msg = "";
// try {
// Bundle data = new Bundle();
// data.putString("my_message", "Hello World");
// data.putString("my_action", "com.google.android.gcm.demo.app.ECHO_NOW");
// String id = Integer.toString(msgId.incrementAndGet());
// gcm.send(SENDER_ID + "@gcm.googleapis.com", id, data);
// msg = "Sent message";
// } catch (IOException ex) {
// msg = "Error :" + ex.getMessage();
// }
// return msg;
// }
// @Override
// protected void onPostExecute(String msg) {
// mDisplay.append(msg + "\n");
// }
// }.execute(null, null, null);
// } else if (view == findViewById(R.id.clear)) {
// mDisplay.setText("");
// }
// }
@Override
protected void onDestroy() {
super.onDestroy();
}
/**
* @return Application's version code from the {@code PackageManager}.
*/
private static int getAppVersion(Context context) {
try {
PackageInfo packageInfo = context.getPackageManager()
.getPackageInfo(context.getPackageName(), 0);
return packageInfo.versionCode;
} catch (NameNotFoundException e) {
// should never happen
throw new RuntimeException("Could not get package name: " + e);
}
}
/**
* @return Application's {@code SharedPreferences}.
*/
private SharedPreferences getGcmPreferences(Context context) {
// This sample app persists the registration ID in shared preferences, but
// how you store the regID in your app is up to you.
return getSharedPreferences(DemoActivity.class.getSimpleName(),
Context.MODE_PRIVATE);
}
/**
* Sends the registration ID to your server over HTTP, so it can use GCM/HTTP or CCS to send
* messages to your app. Not needed for this demo since the device sends upstream messages
* to a server that echoes back the message using the 'from' address in the message.
*/
private void sendRegistrationIdToBackend() {
// Your implementation here.
}
}