标签: android-intentservice

我已经创建了IntentService类和执行asyncTask但onPreExecute()在此代码行调用时获得异常pDialog.show();

AsyncHandlerService类---

public class AsyncHandlerService extends IntentService{
ProgressDialog pDialog;
HttpPost post;
HttpResponse response;
Context ctx;

public AsyncHandlerService() {
    super("AsyncHandlerService");
    ctx = this;
}

@Override
protected void onHandleIntent(Intent intent) {
    new LoadDeviceInfo().execute();   
}


class LoadDeviceInfo extends AsyncTask<String, String, String> {

@Override
protected void onPreExecute() {
    super.onPreExecute();
    pDialog = new ProgressDialog(ctx);
    pDialog.setMessage("Updating device info...");
    pDialog.setIndeterminate(false);
    pDialog.setCancelable(false);
    pDialog.show(); //Exception here..
}

protected String doInBackground(String... args) {
}

protected void onPostExecute(String file_url) {
    pDialog.dismiss();
}

更新:

我 …

我有两个意向服务- IntentServiceA和IntentServiceB

它们具有以下类定义：

public class FirstService extends IntentService {
  public FirstService() {
      super("first_service");
  }

  @Override
  protected void onHandleIntent(Intent intent) {
      Log.d("chi6rag", "first starts");
      for (long i = 0l; i < 10000000l; i++) {
          if (i == 0l) Log.d("chi6rag", "first started");
      }
      Log.d("chi6rag", "first ends");
  }
}

和

public class SecondService extends IntentService {
  public SecondService() {
      super("second_service");
  }

  @Override
  protected void onHandleIntent(Intent intent) {
      Log.d("chi6rag", "second starts");
      for (long i = 0l; i < 10000000l; i++) {
          if …

JobIntentService每当有推送通知进入时，我都会启动该服务，以通知服务获取更多数据。当应用程序处于前台时，一切都会正常进行。

当应用程序在后台运行并且有多个推送通知进入时，该意图被排队，并且它多次执行相同的意图，这给服务器带来了不必要的压力，因为对服务器的第一次调用将获得它需要的所有信息，从而使另一个推送通知中不必要的排队意图。

是否有要取消或不向队列添加相同意图的方法，还是有其他方法可以防止对服务器的额外调用？

我想创建一个类似于这个的服务(从这里引用),以便在Android中异步下载多个文件.

public static class DownloadingService extends IntentService {
public static String PROGRESS_UPDATE_ACTION = DownloadingService.class
        .getName() + ".newDownloadTask";
private ExecutorService mExec;
private CompletionService<NoResultType> mEcs;
private LocalBroadcastManager mBroadcastManager;
private List<DownloadTask> mTasks;

public DownloadingService() {
    super("DownloadingService");
    mExec = Executors.newFixedThreadPool( 3 ); // The reason to use multiple thread is to download files asynchronously. 
    mEcs = new ExecutorCompletionService<NoResultType>(mExec);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    return super.onStartCommand(intent, flags, startId);
}

@Override
protected void onHandleIntent(Intent intent) {

  while(true)
  { …

我正在尝试在后台解压缩一些文件,所以我在google的教程中使用IntentService.我的服务类在AndroidManifest中声明如下:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="org.osmdroid">

<uses-sdk
    android:minSdkVersion="16"
    android:targetSdkVersion="21" />


<application
    android:configChanges="orientation|screenSize|keyboardHidden"
    android:hardwareAccelerated="true"
    android:icon="@drawable/ecn_icon"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >


    <activity
        android:name=".MapActivity"
        android:icon="@drawable/ecn_icon"
        android:label="test" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity
        android:name=".SettingsActivity"
        android:label="@string/title_activity_settings">
    </activity>
    <service
        android:name=".UnZipService"
        android:exported="false"/>
</application>

在活动中,我有

IntentFilter intentFilter = new IntentFilter(DownloadManager
            .ACTION_DOWNLOAD_COMPLETE);

    receiverDownloadComplete = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            long reference = intent.getLongExtra(DownloadManager
                    .EXTRA_DOWNLOAD_ID, -1);
            if (myDownloadReference == reference) {

                     ...
                switch (status) {
                    case DownloadManager.STATUS_SUCCESSFUL:

                        Intent mServiceIntent = new Intent(context, UnZipService.class); …

我不确定它有什么不对!我在这里读到Intentservice本身就是它的子类Context.

public class GCMNotificationIntentService extends IntentService {
    private NotificationManager mNotificationManager;
    NotificationCompat.Builder builder;
    Context mainContext;
    WriteFile writeFile;

    public GCMNotificationIntentService() {
        super("GcmIntentService");
        mainContext = getApplicationContext();
        writeFile = new WriteFile(mainContext);
    }
    // My rest of the code
}

但是我的价值是空的mainContext.任何建议都是最受欢迎的.

所以IntentService当我运行一次时,我运行正常.它需要一个图像处理它然后输出一系列RGB值.

但我现在需要它做的是多次运行批处理一系列图像.我的第一次尝试涉及在我的主类中调用停止服务,然后创建并运行IntentService的新实例.但是当我调用StopService时,这个崩溃了.

有没有正确的方法来做到这一点？

我想了解Application对象的生命周期Android,尤其是IntentService.

如果IntentService启动,Application对象是否会随之启动？这个的确切顺序是什么？最后,在这种情况下什么时候会被销毁？

我在Crashlytics中看到崩溃：

致命异常：java.lang.NullPointerException：尝试在com.myapp.APKOfferQueueManagerIntentService.onHandleIntent（SourceFile：71）上的空对象引用上调用虚拟方法'int android.content.Intent.getIntExtra（java.lang.String，int）' ），位于android.os.Looper.loop（Looper.java:135）的android.os.Handler.dispatchMessage（Handler.java:102）的android.app.IntentService $ ServiceHandler.handleMessage（IntentService.java:65） .os.HandlerThread.run（HandlerThread.java:61）

用空意图触发IntentService怎么可能？

我创建了一个IntentService,如下所示:

    public class OrdersSyncService extends IntentService {

    private static final String TAG = OrdersSyncService.class.getSimpleName();

    private Order orderObject;

    public OrdersSyncService() {
        super("OrdersSyncService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {

        //Util.showToast(getApplicationContext(), "Syncing Orders........");
        Log.d(TAG, "I'm running....");
        syncOrders();
    }

    private void syncOrders() {

        Database database = CouchBaseHelper.openCouchBaseDB(this);
        JSONArray ordersJsonArray = new JSONArray(CouchBaseHelper.retrieveNotSyncedOrders(database));
        if (ordersJsonArray.length() != 0) {
            uploadOrders(ordersJsonArray.toString());
            Log.d(TAG, "Orders syncing started.");
        } else {
            Log.d(TAG, "Nothing to sync.");
        }
    }

    private void uploadOrders(String ordersJsonArray) {

        RetrofitApi.ApiInterface apiInterface = RetrofitApi.getApiInterfaceInstance();
        final Call<Order> uploadOrders …