当我在服务的onStartCommand（）之外使用Intent时，为了显示特定事件的通知，它会在null对象引用上显示getApplicationContext。 Service仅允许在onStartCommand（）方法中使用getApplcationContext / this / context。 如何在onStartCommand（）方法之外使用它？ 以下是我的服务。有人可以帮我解决这个问题吗？
public class ForegroundService extends Service {
@Nullable
private static TransferUtility transferUtility;
private static ArrayList<HashMap<String, Object>> transferRecordMaps;
private static ArrayList<HashMap<String, Object>> transferRecordMaps1;
private Utils utils = new Utils();
private static final int INDEX_NOT_CHECKED = -1;
public static int totalcount, totalAssetCount;
private int checkedIndex;
private static List<TransferObserver> observers;
private static int REQUEST_CAMERA = 0, navigate = 0,counter=0,failedcounter=0;
private static final String LOG_TAG = "ForegroundService";
UploadMediaToAssetFragment uploadMediaToAssetFragment;
private int progress;
Context context;
private long currentbyte, totalbyte;
private Notification notification;
@Override
public void onCreate() {
super.onCreate();
transferUtility = Util.getTransferUtility(getApplicationContext());
checkedIndex = INDEX_NOT_CHECKED;
transferRecordMaps = new ArrayList<HashMap<String, Object>>();
transferRecordMaps1 = new ArrayList<HashMap<String, Object>>();
uploadMediaToAssetFragment = new UploadMediaToAssetFragment();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (intent.getAction().equals(Constants.ACTION.STARTFOREGROUND_ACTION)) {
Log.i(LOG_TAG, "Received Start Foreground Intent ");
Intent notificationIntent = new Intent(this, UploadMediaToAssetFragment.class);
notificationIntent.setAction(Constants.ACTION.MAIN_ACTION);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
| Intent.FLAG_ACTIVITY_CLEAR_TASK);
Log.d(LOG_TAG,"bytes"+UploadMediaToAssetFragment.totalAssetCount+ " total"+UploadMediaToAssetFragment.totalcount);
uploadAsset();
initData();
updateList();
// AlertDialog.Builder builder = new AlertDialog.Builder(this);
// builder.setTitle("Test dialog");
// builder.setIcon(R.drawable.icon);
// builder.setMessage("Content");
//
// AlertDialog alert = builder.create();
// alert.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
// alert.show();
// startActivity(notificationIntent);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
notificationIntent, 0);
Intent previousIntent = new Intent(this, ForegroundService.class);
previousIntent.setAction(Constants.ACTION.PREV_ACTION);
PendingIntent ppreviousIntent = PendingIntent.getService(this, 0,
previousIntent, 0);
Intent playIntent = new Intent(this, ForegroundService.class);
playIntent.setAction(Constants.ACTION.PLAY_ACTION);
PendingIntent pplayIntent = PendingIntent.getService(this, 0,
playIntent, 0);
Intent nextIntent = new Intent(this, ForegroundService.class);
nextIntent.setAction(Constants.ACTION.NEXT_ACTION);
PendingIntent pnextIntent = PendingIntent.getService(this, 0,
nextIntent, 0);
Bitmap icon = BitmapFactory.decodeResource(getResources(),
R.drawable.logo);
notification = new NotificationCompat.Builder(this)
.setContentTitle("Visibly")
.setTicker("asset uplaoding")
.setContentText("uploading")
.setSmallIcon(R.drawable.ic_launcher)
.setLargeIcon(
Bitmap.createScaledBitmap(icon, 128, 128, false))
.setContentIntent(pendingIntent)
.setOngoing(true)
.setProgress(100,progress,false)
.addAction(android.R.drawable.ic_menu_close_clear_cancel,
"cancel", ppreviousIntent).build();
startForeground(Constants.NOTIFICATION_ID.FOREGROUND_SERVICE,
notification);
// if(UploadMediaToAssetFragment.totalAssetCount>=UploadMediaToAssetFragment.totalcount)
// {
// onDestroy();
// stopForeground(true);
// stopSelf();
// }
} else if (intent.getAction().equals(Constants.ACTION.PREV_ACTION)) {
Log.i(LOG_TAG, "Clicked Previous");
} else if (intent.getAction().equals(Constants.ACTION.PLAY_ACTION)) {
Log.i(LOG_TAG, "Clicked Play");
} else if (intent.getAction().equals(Constants.ACTION.NEXT_ACTION)) {
Log.i(LOG_TAG, "Clicked Next");
} else if (intent.getAction().equals(
Constants.ACTION.STOPFOREGROUND_ACTION)) {
Log.i(LOG_TAG, "Received Stop Foreground Intent");
stopForeground(true);
stopSelf();
}
return START_STICKY;
}
@Override
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroy");
}
public IBinder onBind(Intent intent) {
return null;
}
public class ForegroundServiceBInder extends Binder {
ForegroundService getService() {
// Return this instance of LocalService so clients can call public methods
return ForegroundService.this;
}
}
public void uploadAsset()
{
Log.d("upload asset service","method called");
for(int i=0;i<AddMediaAssetActivity.galleryDTOArrayList1.size();i++)
{
Handler handler1 = new Handler();
try {
if(AddMediaAssetActivity.galleryDTOArrayList1.get(i)!=null)
{
String path;
Uri uri = Uri.fromFile(new File(AddMediaAssetActivity.galleryDTOArrayList1.get(i).getMediaName()));
path = Utility.getPath(uri, getApplicationContext());
Uri uriThumb = Uri.fromFile(new File(AddMediaAssetActivity.galleryDTOArrayList1.get(i).getThumbnail()));
String pathThum = null;
if (uriThumb != null)
pathThum = Utility.getPath(uriThumb, getApplicationContext());
path = Utility.getPath(uri, getApplicationContext());
if(GlobalVariables.isNetworkAvailable(getApplicationContext())) {
beginUpload1(pathThum, pathThum);
beginUpload(path, AddMediaAssetActivity.galleryDTOArrayList1.get(i).getDescription(), pathThum,AddMediaAssetActivity.galleryDTOArrayList1.get(i).getCreateTagPostDTOList());
}else
{
AlertDialog.Builder builder;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
builder = new AlertDialog.Builder(getApplicationContext(),android.R.style.Theme_Material_Light_Dialog_Alert);
} else {
builder = new AlertDialog.Builder(getApplicationContext());
}
builder.setMessage(getResources().getString(R.string.network_connectivity))
.setTitle("");
builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id)
{
//getApplicationContext().finish();
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.setCanceledOnTouchOutside(true);
dialog.show();
dialog.getButton(dialog.BUTTON_POSITIVE).setTextColor(getResources().getColor(R.color.clear_blue));
}
}
}catch (Exception e)
{
}
}
}
/*
* Begins to upload the file specified by the file path.
*/
private void beginUpload(String filePath, String title, String pathThum, List<TagDTO> createTagPostDTOList)
{
Log.d("beginUpload","method called "+filePath+" title "+title+" pathnum "+pathThum+" list tagdto"+createTagPostDTOList);
if (filePath == null) {
Toast.makeText(getApplicationContext(), "Could not find the filepath of the selected file",
Toast.LENGTH_LONG).show();
return;
}
File file = new File(filePath);
TransferObserver observer = transferUtility.upload(Constants.BUCKET_NAME, Constants.FOLDERNAME_NAME+"/"+ file.getName(),
file, CannedAccessControlList.PublicRead);
File file1 = new File(pathThum);
AssetMediaDTO assetMediaDTO=new AssetMediaDTO();
if(GlobalVariables.isCampaignAsset)
{
if (GlobalVariables.campaignFeedDTO.getCampaign_category() != null && GlobalVariables.campaignFeedDTO.getCampaign_category().length() > 0 && !(GlobalVariables.campaignFeedDTO.getCampaign_category().equalsIgnoreCase("null"))) {
assetMediaDTO.setCategory_id(GlobalVariables.campaignFeedDTO.getCampaign_category());
} else {
assetMediaDTO.setCategory_id("rpPDp");
}
if (GlobalVariables.campaignFeedDTO.getCampaign_folder() != null && GlobalVariables.campaignFeedDTO.getCampaign_folder().length() > 0 && !(GlobalVariables.campaignFeedDTO.getCampaign_folder().equalsIgnoreCase("null"))) {
if(GlobalVariables.campaignFeedDTO.getCampaign_folder().equalsIgnoreCase("General"))
{
assetMediaDTO.setFolder_id("");
}else
{
assetMediaDTO.setFolder_id(GlobalVariables.campaignFeedDTO.getCampaign_folder());
}
} else
{
assetMediaDTO.setFolder_id("");
}
}else
{
if (AssetFolderActivity.folderDTO.getCategoryID() != null && AssetFolderActivity.folderDTO.getCategoryID().length() > 0 && !(AssetFolderActivity.folderDTO.getCategoryID().equalsIgnoreCase("null"))) {
assetMediaDTO.setCategory_id(AssetFolderActivity.folderDTO.getCategoryID());
} else {
assetMediaDTO.setCategory_id("rpPDp");
}
if (AssetFolderActivity.folderDTO.getFolderIdentity() != null && AssetFolderActivity.folderDTO.getFolderIdentity().length() > 0 && !(AssetFolderActivity.folderDTO.getFolderIdentity().equalsIgnoreCase("null"))) {
if(AssetFolderActivity.folderDTO.getFoldername()!=null&&AssetFolderActivity.folderDTO.getFoldername().equalsIgnoreCase("general"))
{
assetMediaDTO.setFolder_id("");
}else {
assetMediaDTO.setFolder_id(AssetFolderActivity.folderDTO.getFolderIdentity());
}
} else {
assetMediaDTO.setFolder_id("");
}
}
assetMediaDTO.setMedia_url(GlobalVariables.s3Path+Constants.FOLDERNAME_NAME+"/"+file.getName());
assetMediaDTO.setThumbnail_url(GlobalVariables.s3Path+Constants.FOLDERNAME_NAME+"/"+file1.getName());
try {
assetMediaDTO.setMediaSize(""+file.length());
}catch (Exception e)
{
}
assetMediaDTO.setDetail(title);
String result = file.getName().substring(0, file.getName().lastIndexOf("."));
assetMediaDTO.setTitle(result);
assetMediaDTO.setTagDTOList(createTagPostDTOList);
GlobalVariables.assetMediaDTOList.add(assetMediaDTO);
}
/*
* Begins to upload the file specified by the file path.
*/
private void beginUpload1(String filePath, String pathThum) {
Log.d("beginUpload1","method called");
if (filePath == null) {
Toast.makeText(getApplicationContext(), "Could not find the filepath of the selected file",
Toast.LENGTH_LONG).show();
return;
}
File file = new File(filePath);
TransferObserver observer = transferUtility.upload(Constants.BUCKET_NAME, Constants.FOLDERNAME_NAME+"/"+ file.getName(),
file,CannedAccessControlList.PublicRead);
// temp1=file.getName();
}
//To delete assets from list
public void deleteMediaUpload(final int position)
{
final int position1=position+1;
AlertDialog.Builder builder;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
builder = new AlertDialog.Builder(GlobalVariables.mActivity, android.R.style.Theme_Material_Light_Dialog_Alert);
} else {
builder = new AlertDialog.Builder(GlobalVariables.mActivity);
}
builder.setMessage("Do you want to delete this media?")
.setTitle("");
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id)
{
dialog.dismiss();
if (position >= 0 && position1 < observers.size())
{
try {
transferUtility.deleteTransferRecord(observers.get(position).getId());
transferUtility.deleteTransferRecord(observers.get(position1).getId());
observers.remove(position1);
transferRecordMaps.remove(position1);
observers.remove(position);
transferRecordMaps.remove(position);
AddMediaAssetActivity.galleryDTOArrayList1.remove(position);
}catch (Exception e)
{
}
updateList();
try {
GlobalVariables.assetMediaDTOList.remove(position);
}catch (Exception e)
{
}
}
}
});
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id)
{
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.setCanceledOnTouchOutside(false);
dialog.show();
dialog.getButton(dialog.BUTTON_NEGATIVE).setTextColor(GlobalVariables.mActivity.getResources().getColor(R.color.clear_blue));
dialog.getButton(dialog.BUTTON_POSITIVE).setTextColor(GlobalVariables.mActivity.getResources().getColor(R.color.clear_blue));
}
// /**
// * Gets all relevant transfers from the Transfer Service for populating the
// * UI
// */
// private void initData() {
// counter=0;
// failedcounter=0;
// navigate=0;
// transferRecordMaps.clear();
// transferRecordMaps1.clear();
// // Use TransferUtility to get all upload transfers.
// observers = transferUtility.getTransfersWithType(TransferType.UPLOAD);
// TransferListener listener = new UploadMediaToAssetFragment.UploadListener();
// for (TransferObserver observer : observers) {
//
// // For each transfer we will will create an entry in
// // transferRecordMaps which will display
// // as a single row in the UI
// HashMap<String, Object> map = new HashMap<String, Object>();
// Util.fillMap(map, observer, false);
//
// transferRecordMaps.add(map);
//
// // Sets listeners to in progress transfers
// if (TransferState.WAITING.equals(observer.getState())
// || TransferState.WAITING_FOR_NETWORK.equals(observer.getState())
// || TransferState.IN_PROGRESS.equals(observer.getState())) {
// observer.setTransferListener(listener);
// }
// }
// transferRecordMaps1.clear();
// for(int i=0;i<transferRecordMaps.size();i++)
// {
// File file = new File((String) transferRecordMaps.get(i).get("fileName"));
// if(file.getName().substring(0,2).equalsIgnoreCase("0!"))
// {
// }
// else
// {
// transferRecordMaps1.add(transferRecordMaps.get(i));
//
// }
//
// }
// assetListAdapter.notifyDataSetChanged();
// }
/*
* A TransferListener class that can listen to a upload task and be notified
* when the status changes.
*/
public class UploadListener implements TransferListener {
// Simply updates the UI list when notified.
@Override
public void onError(int id, Exception e)
{
failedcounter++;
updateList();
}
@Override
public void onProgressChanged(int id, long bytesCurrent, long bytesTotal) {
updateList();
currentbyte =bytesCurrent;
totalbyte =bytesTotal;
Log.d("onprogresschnaged","method bytes"+bytesCurrent+" bytestotoal"+bytesTotal);
}
@Override
public void onStateChanged(int id, TransferState newState)
{
if (newState.equals(TransferState.COMPLETED))
{
counter++;
updateList();
} else if (newState.equals(TransferState.FAILED))
{
failedcounter++;
updateList();
}
}
}
/*
* Updates the ListView according to the observers.
*/
/*
* Updates the ListView according to the observers.
*/
public void updateList()
{
if(transferRecordMaps!=null&&transferRecordMaps.size()>0)
{
TransferObserver observer = null;
HashMap<String, Object> map = null;
for (int i = 0; i < observers.size(); i++) {
observer = observers.get(i);
map = transferRecordMaps.get(i);
progress = (int) ((double) observer.getBytesTransferred() * 100 / observer
.getBytesTotal());
Log.d("progressuploadingData"," map"+progress);
Util.fillMap(map, observer, i == checkedIndex);
Log.d("uploadingData"," map"+map+" observer"+observer);
}
transferRecordMaps1.clear();
for (int i = 0; i < transferRecordMaps.size(); i++)
{
File file = new File((String) transferRecordMaps.get(i).get("fileName"));
if (file.getName().substring(0, 2).equalsIgnoreCase("0!")) {
} else
{
transferRecordMaps1.add(transferRecordMaps.get(i));
}
totalcount=transferRecordMaps.size();
totalAssetCount=counter+failedcounter;
Log.d("totalcount","count"+totalcount+"toatlassetcount"+totalAssetCount);
if(counter>1&&totalAssetCount>=totalcount&&GlobalVariables.assetMediaDTOList.size()>0)
{
Log.d("myservice asset","complete");
navigate=1;
Intent intent = new Intent(this, DialogeActivity.class);
context.getApplicationContext().startActivity(intent);
// Toast.makeText(this,"Your asset uploaded successfully",Toast.LENGTH_LONG).show();
// Intent notificationIntent = new Intent(this, DialogeActivity.class);
// notificationIntent.setAction(Constants.ACTION.MAIN_ACTION);
// notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK
// | Intent.FLAG_ACTIVITY_CLEAR_TASK);
// startActivity(notificationIntent);
// Notification notification = new NotificationCompat.Builder(this)
// .setContentTitle("Visibly")
// .setTicker("asset uploaded")
// .setContentText("asset uploaded successfully")
// .setSmallIcon(R.drawable.ic_launcher)
// .build();
// AlertDialog.Builder builder = new AlertDialog.Builder(this);
// builder.setTitle("Test dialog");
// builder.setIcon(R.drawable.icon);
// builder.setMessage("Content");
// builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
// public void onClick(DialogInterface dialog, int whichButton) {
// //Do something
// dialog.dismiss();
// });
//
// AlertDialog alert = builder.create();
// alert.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
// alert.show();
// AlertDialog alertDialog = new AlertDialog.Builder(this)
// .setTitle("Title")
// .setMessage("Are you sure?")
// .create();
//
// alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
// alertDialog.show();
// button_Done.setVisibility(View.VISIBLE);
// button_Done.setText("Done");
// button_Done.setEnabled(true);
// button_Done.setClickable(true);
}else if(failedcounter>=totalcount)
{
navigate=0;
// button_Done.setVisibility(View.VISIBLE);
// button_Done.setText("Back");
// button_Done.setEnabled(true);
// button_Done.setClickable(true);
}else
{
// button_Done.setVisibility(View.VISIBLE);
// button_Done.setText("Please wait.");
// button_Done.setEnabled(false);
// button_Done.setClickable(false);
}
}
// assetListAdapter.notifyDataSetChanged();
}else
{
// Intent intent=null;
// if( AssetFolderActivity.folderDTO!=null&&AssetFolderActivity.folderDTO.getFolderIdentity()!=null&& AssetFolderActivity.folderDTO.getFolderIdentity().length()>0&&!AssetFolderActivity.folderDTO.getFolderIdentity().equalsIgnoreCase("")) {
// intent = new Intent(activity, AssetFolderActivity.class);
// }else
// {
// intent = new Intent(activity, DashboardActivity.class);
// }
// intent.putExtra("folderDTO", AssetFolderActivity.folderDTO);
// activity.startActivity(intent);
// activity.finish();
}
}
private void initData() {
counter=0;
failedcounter=0;
navigate=0;
transferRecordMaps.clear();
transferRecordMaps1.clear();
// Use TransferUtility to get all upload transfers.
observers = transferUtility.getTransfersWithType(TransferType.UPLOAD);
TransferListener listener = new ForegroundService().new UploadListener();
for (TransferObserver observer : observers) {
// For each transfer we will will create an entry in
// transferRecordMaps which will display
// as a single row in the UI
HashMap<String, Object> map = new HashMap<String, Object>();
Util.fillMap(map, observer, false);
transferRecordMaps.add(map);
// Sets listeners to in progress transfers
if (TransferState.WAITING.equals(observer.getState())
|| TransferState.WAITING_FOR_NETWORK.equals(observer.getState())
|| TransferState.IN_PROGRESS.equals(observer.getState())) {
observer.setTransferListener(listener);
}
}
transferRecordMaps1.clear();
for(int i=0;i<transferRecordMaps.size();i++)
{
File file = new File((String) transferRecordMaps.get(i).get("fileName"));
if(file.getName().substring(0,2).equalsIgnoreCase("0!"))
{
}
else
{
transferRecordMaps1.add(transferRecordMaps.get(i));
}
}
// assetListAdapter.notifyDataSetChanged();
}
}
答案 0 :(得分：0)
服务只允许在onStartCommand（）方法中使用getApplcationContext / this / context
没有这样的限制。您可以在Service上的其他方法中使用该方法，只要onCreate()已调用Service。
因此，要显示来自某个后台帖子的Notification，Service onStartCommand()来自this，请使用if (instance1 == instance2) //...
。
答案 1 :(得分：0)
服务是Context类的子级，可在您需要时为您提供上下文。 它的行为就像一个活动（也是上下文的孩子。）
与活动相同，您可以将this或yourService.this（在匿名类中）关键字作为上下文调用。
答案 2 :(得分：0)
在updateList()中执行此操作：
context.getApplicationContext().startActivity(intent);
context是Service的成员变量。但是，您永远不会将此变量初始化为任何内容。因此它是null，这将导致您描述的错误。
答案 3 :(得分：-1)
服务有自己的背景。有一个简单的方法来拥有一个globl上下文。
private Context context;
@Override
public int onStartCommand(@Nullable Intent intent, int flags, int startId) {
context = this;
}
这就是全部。应该工作，如果不是在其他地方搜索问题。
@Edit
为清楚起见，您的问题导致此行，因为您的上下文未分配，并且它为空。
context.getApplicationContext().startActivity(intent);