I have a huge database (40MB) on an SDCard. I need fetch data, with LIKE in query, which is very slow.
DB request takes about 5 seconds. Therefore, I need to do it asynchronously and with ProgressDialog.
I tried it with AsyncTask, but problem is with ProgressDialog. It was implemented this way:
private class GetDataFromLangDB extends AsyncTask<String, String, String> {
private final ProgressDialog dialog = new ProgressDialog(TranslAndActivity.this);
#Override
protected void onPreExecute() {
super.onPreExecute();
urDBCursor.close();
curDBCursor = null;
scaAdapter = null;
this.dialog.setMessage("Loading data...");
this.dialog.show();
}
#Override
protected String doInBackground(String... whatSearch) {
String result = "";
if (myDatabaseAdapter != null) {
curDBCursor = myDatabaseAdapter.fetchAll(whatSearch[0]);
}
return result;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
prepareListView();
}
}
The problem is that ProgressDialog is not shown during the DB request.
After finished database query, it flash on screen for a short time. When user tries
to tap on screen during database request, UI is freezed, and after DB request
message about 'not responding' is shown.
I tried it with a thread this way:
public void startProgress(View view, final String aWhatSearch) {
final ProgressDialog dialog = new ProgressDialog(MyActivity.this);
if (curDBCursor != null){
curDBCursor.close();
curDBCursor = null;
}
dialog.setMessage("Loading data...");
dialog.show();
Runnable runnable = new Runnable() {
public void run() {
curDBCursor = myDatabaseAdapter.fetchAll(aWhatSearch);
// dirty trick
try {
Thread.sleep(250); // it must be here to show progress
} catch (InterruptedException e) {
e.printStackTrace();
}
handler.post(new Runnable() {
public void run() {
if (dialog.isShowing()) {
dialog.dismiss();
}
prepareListView();
}
});
}
};
new Thread(runnable).start();
}
The result was the same, but when I used the trick with Thread.sleep(250);
ProgressDialog was shown during the database request. But it is not spinning,
it looks freezed during the DB request.
DB stuff is called this way (after tap on search button):
btnSearchAll.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// AsyncTask
new GetDataFromLangDB().execute(edtTextToSearch.getText().toString());
// or Thread
//startProgress(null, edtTextToSearch.getText().toString());
}
});
I found a lot of problems like this in SO, but nothing was useful for me.
Could it be that DB is on SD Card?
I put the definition of the dialog into the AsyncTask Class and it works fine for me.
Take a look at this exampel (You have to change NAMEOFCLASS in the name of your CLASS:
private class doInBackground extends AsyncTask<Integer, Integer, Void> {
final ProgressDialog dialog = new ProgressDialog(NAMEOFCLASS.this) {
#Override
protected void onPreExecute() {
dialog.setCancelable(false);
dialog.setTitle(getString(R.string.daten_wait_titel));
dialog.setIcon(R.drawable.icon);
dialog.setMessage(getString(R.string.dse_dialog_speichern));
dialog.show();
}
#Override
protected void onCancelled() {
dialog.cancel();
}
....
#Override
protected void onProgressUpdate(Integer... values) {
// DO YOUR UPDATE HERE
}
#Override
protected void onPostExecute(Void result) {
dialog.dismiss();
}
}
Maybe this SO answer could help you. It looks like similar problem. Try to use AsyncQueryHandler for querying your database
declare you Dialog box on Class (Activity) level like this
private ProgressDialog dialog = null;
show the progress dialog and call the AsyncTask class when you want to start you Busy work..like onButton click or any
dialog = ProgressDialog.show(this,"Sending Email to your account please! wait...", true);
SendingEmailTask task = new SendingEmailTask();
String s = "";
task.execute(s);
create your inner class like
private class SendingEmailTask extends AsyncTask<String, Void, String> {
protected String doInBackground(String... urls) {
//do your work here..
// like fetching the Data from DB or any
return null;
}
#Override
protected void onPostExecute(String str) {
//hide progress dialog here
dialog.dismiss();
}
}
let me know if this help!!
Related
I have problems with showing up a ProgressDialog:
The following snippet shows my code in an example:
public override void OnActivityCreated(Bundle savedInstanceState)
{
base.OnActivityCreated(savedInstanceState);
progressDialog = new ProgressDialog(Context);
progressDialog.SetCancelable(false);
progressDialog.SetMessage("Saving ...");
}
private void Method()
{
progressDialog.Show();
var testDialog = progressDialog.IsShowing;
SaveImage();
}
private void SaveImage()
{
// does lot
...
// especially this method takes some time
mutableBitmap.Compress(Bitmap.CompressFormat.Png, 100, stream);
}
I create a ProgressDialog, which I want to show before calling the SaveImage Method (and Cancel it when SaveImage is done).
My problem is that the ProgressDialog will not be displayed until the SaveImage Method is done.
In Debug-Mode, progressDialog.IsShowing is true, before the SaveImage-Method is called, but it is not displayed.
You will have to shift your IO related code to a background thread, you can use an asynctask for this
private class AsyncTaskRunner extends AsyncTask<String, String, String> {
private String resp;
ProgressDialog progressDialog;
#Override
protected String doInBackground(String... params) {
saveImage();
}
#Override
protected void onPostExecute(String result) {
// execution of result of Long time consuming operation
progressDialog.dismiss();
}
#Override
protected void onPreExecute() {
progressDialog = ProgressDialog.show(getContext(),
"ProgressDialog",
"Loading");
}
}
I found a solution that works fine for me:
private async void Method()
{
progressDialog.Show();
var thread = new System.Threading.Thread(new ThreadStart(delegate
{
SaveImage();
}));
thread.Start();
while(thread.ThreadState == ThreadState.Running)
{
await Task.Delay(100);
}
progressDialog.Dismiss();
}
Meanwhile, I outsourced this code into a public static class ThreadHelper, that just takes an Action (in this case SaveImage()) and a ProgressDialog as parameters.
I have a progress dialog, I want it to show and dismiss when my method has finished executing. now, I have this:
progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Downloading...");
progressDialog.show();
new Thread(new Runnable() {
#Override
public void run() {
try{
DownloadMethod(s);
progressDialog.dismiss();
}catch (Exception e){
Toast.makeText(prefs.this, "We can't reach the data...Try again", Toast.LENGTH_SHORT).show();
}
}
}).start();
My method DownloadMethod is executed but never shows the dialog.
Actually, It must be throwing an exception with progressDialog.dismiss(); call because you cannot update UI from a worker thread, instead use AsyncTask
e.g pass parameter to constructor
private class DownloadFilesTask extends AsyncTask<Void, Void, Void> {
TypeOf_S s;
public DownloadFilesTask(TypeOf_S s){
this.s = s;
}
#Override
protected Void doInBackground(Void... obj) {
DownloadMethod(s);
return null;
}
#Override
protected void onPostExecute(Void result) {
progressDialog.dismiss();
}
}
and call it like new DownloadFilesTask(s).execute();
or with generic parameter
private class DownloadFilesTask extends AsyncTask<TypeOf_S, Void, Void> {
#Override
protected Void doInBackground(TypeOf_S... obj) {
DownloadMethod(obj[0]);
return null;
}
#Override
protected void onPostExecute(Void result) {
progressDialog.dismiss();
}
}
and call it like new DownloadFilesTask().execute(s);
progressDialog.dismiss();is throwing an exception so move your code inside runOnUiThread() method like this:
runOnUiThread(new Runnable() {
#Override
public void run() {
progressDialog.dismiss();
}
});
as suggested by Pavneet you can use async task as follows where AsyncTask<String, void, String> corresponds to the input type progress value and last is result value you are interested so give data types accordingly.
private class DownloadFilesTask extends AsyncTask<String, void, String> {
protected String doInBackground(String... urls) {
//here do the actual downloading instead of calling the DownloadMethod(s)
}
protected void onPreExecute() {
//here show the dialog
progressDialog.show();
}
protected void onPostExecute(String result) {
//here hide the dialog
progressDialog.dismiss();
}
}
and where you are calling the download function you just call this
progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Downloading...");
new DownloadFilesTask().execute(s);
//here s is assumed to be string type you can give anything
I am trying to use progress bar while updating my database. Good thing, i can successfully update my database but my progress bar is not showing. I am using a progress bar the will show also the percentage on my update. I don't know what wrong with my code below, help me figure it out please:
public class SyncBrand extends AsyncTask<String, Void, Boolean>
{
public static final int BRAND_DIALOG_DOWNLOAD_PROGRESS = 0;
public SyncBrand(Context context, String _username, String _password, String _code,String _remarks,String _date,String _province,String _infotype,
String _competitor,ArrayList<String> _brands, ArrayList<String> _segments)
{
....
}
protected Dialog onCreateDialog(int id) {
switch (id) {
case BRAND_DIALOG_DOWNLOAD_PROGRESS:
progressDialog = new ProgressDialog(mContext);
progressDialog.setMessage("Updating Sub Brands..");
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.setCancelable(false);
progressDialog.show();
return progressDialog;
default:
return null;
}
}
#SuppressWarnings("deprecation")
protected void onPreExecute()
{
super.onPreExecute();
((Activity) mContext).showDialog(BRAND_DIALOG_DOWNLOAD_PROGRESS);
}
protected Boolean doInBackground(String... arg0)
{
try{
....
}catch (Exception e){
Log.e("Update SubBrand", "Error:", e);
exception = e;
return false;
}
....
return true;
}
protected void onProgressUpdate(String... progress) {
Log.d("ANDRO_ASYNC",progress[0]);
progressDialog.setProgress(Integer.parseInt(progress[0]));
}
#SuppressWarnings("deprecation")
protected void onPostExecute(Boolean valid)
{
((Activity) mContext).removeDialog(BRAND_DIALOG_DOWNLOAD_PROGRESS);
if(valid){
.....
}else{
Toast.makeText(mContext, "Failed to update.Please try again.", Toast.LENGTH_SHORT).show();
mContext.startActivity(new Intent(mContext, S_2nd_Main.class));
}
}
}
A couple problems I see here. You have Void for the second argument in your AsyncTask
public class SyncBrand extends AsyncTask<String, Void, Boolean>
which means that onProgressUpdate() should expect that type of data passed to it but you have protected void onProgressUpdate(String... progress) { which tells that method to take a String parameter. Also, you don't call publishProgress() from doInBackground() which is what is used to call onProgressUpdate().
Change your AsyncTask to
public class SyncBrand extends AsyncTask<String, String, Boolean>
and add publishProgress() to doInBackground() and pass the String value you want it to update the ProgressDialog to.
I defined an AsyncTask in a button's onclicklistener, and once user clicks the button, ideally progress dialog shows while asynctask downloading.
However, progress dialog just flashes in and disappears before the results returned, and the button gets focused while the asynctask works in the background.
Can someone help me figure out what I did wrong here? Code snippet:
final ProgressDialog progressDialog = new ProgressDialog(context);
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
((Button)findViewById(R.id.buttonLoginActivity)).setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
AsyncTask<Void, Void, Void> downloadTask= new AsyncTask<Void, Void, Void>(){
#Override
protected Void doInBackground(Void... params) {
String data = Service.getSomeData();
context.getContentResolver.notifyChange("content://some_url");
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if(progressDialog== null) return;
if(progressDialog!=null) {
progressDialog.dismiss();
progressDialog = null;
}
}
};
progressDialog.show();
downloadTask.execute();
try{
downloadTask.get();
}catch(Exception e){
e.printStackTrace();
return;
}
}
});
Don't use get()
downloadTask.get();
this is a blocking call. From the Docs
Waits if necessary for the computation to complete, and then retrieves its result.
Just use execute() as you are then do what you need with the results in onPostExecute()
show the progressDialog on the onPreExecute which need to be writen, and it will run on the UI thread, not in background ( android 4 )
also I would call the async task on a new Handler().post(myAsynctaskcaller)
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog.show();
}
In my code I load a spinner adapter by using Async Task
In My case The ProgressDialog is Not dismissing
This is My code.
I want to show the item after adapter load and the progressDialog is to dismiss
Please Help me, Thanks
private class LoadMoreVehicals extends AsyncTask<Object, Integer, Object> {
#Override
protected void onPreExecute() {
progressBar = ProgressDialog.show(RegistrationScreen.this, "",
"Loading...");
progressBar.setIndeterminate(true);
progressBar.setIndeterminateDrawable(getResources().getDrawable(
R.anim.progressbar_handler));
super.onPreExecute();
}
#Override
protected Object doInBackground(Object... params) {
String countryUrl = ConstantURL.COUNTRY_URL;
getCounty(countryUrl);
countrySpinner
.setAdapter(new MyCustomSpinnerAdapter(
RegistrationScreen.this,
R.layout.spinner_dropdown,
countyList));
return null;
}
#Override
protected void onProgressUpdate(Integer... values) {
progressBar.getProgress();
}
#Override
protected void onPostExecute(Object result) {
progressBar.dismiss();
Log.e("Im in onPostExecute", "");
super.onPostExecute(result);
}
}
While programming in Android you should remember one thing that any task which draws something on the screen should be executed on the main thread. When you set the adapter then android calls the getView() method of the adapter and draws views on the screen. So you should set the adapter in the postExecute() method instead in doInBackground() method.
Here is a small sample to clear my point:
class MyTask extends AsyncTask<Void, Void, Void> {
ProgressDialog pd = new ProgressDialog(MainActivity.this);
#Override
protected void onPreExecute ( )
{
//starting the progress dialogue
pd.show();
}
#Override
protected Void doInBackground (Void... params)
{
//fetch data here
...
...
return null;
}
#Override
protected void onPostExecute (Void result)
{
//set adapter here
...
...
//dismissing the progress dialogue
pd.dismiss();
}
}
In my experience i have so many problems with async runs and UI so now always separate the stuff trying to place the "responsibilities" in each place. So i do something like this:
Create my Async class with the process i want to do and nothing that transform the UI in it
Create a function in UI thread that modify the UI when async task finish, something like OnAsyncTaskComplete(Object response)
Keep communicated the threads
public class MyActivity extends Activity {
private static MyAsyncClass backgroundTask;
private static ProgressDialog pleaseWaitDialog;
//......activity stuff.......
#Override
public void onPause()
{
super.onPause();
//Get rid of progress dialog in the event of a screen rotation or other state change. Prevents a crash.
if (pleaseWaitDialog != null)
pleaseWaitDialog.dismiss();
}
//Function to avoid lose the async thread if the app interrupts (phone rotation, incoming call, etc) RECOMENDED TO HANDLE THIS!!
//Sets the current state after app resume
#Override
public void onResume()
{
super.onResume();
//If there is a background task set it to the new activity
if ((backgroundTask != null) && (backgroundTask.getStatus() == Status.RUNNING))
{
if (pleaseWaitDialog != null)
pleaseWaitDialog.show();
backgroundTask.setActivity(this);
}
}
}
//Logic business after the web service complete here
//Do the thing that modify the UI in a function like this
private void onTaskCompleted(Object _response)
{
//For example _response can be a new adapter
MyList.setAdapter((BaseAdapter)_response);
//or can be a list to create the new adapter
MyList.setAdapter(new MyAdapter(this, (ArrayList<String>)_response));
//or can be anything you want, just try to make here the things that you need to change the UI
}
/**
* Class that handle the async task
*/
public class MyAsyncClass extends AsyncTask<Void, Void, Object>
{
//Maintain attached activity for states change propose
private MyActivity activity;
//Keep the response of the async task
private Object _response;
//Flag that keep async task completed status
private boolean completed;
//Constructor
private MyAsyncClass(MyActivity activity) {
this.activity = activity;
}
//Pre execution actions
#Override
protected void onPreExecute() {
//Start the splash screen dialog
if (pleaseWaitDialog == null)
pleaseWaitDialog= ProgressDialog.show(activity.this,
"PLEASE WAIT",
"Getting results...",
false);
}
//Execution of the async task
protected Object doInBackground(Object...params)
{
//return the thing you want or do want you want
return new ArrayList();
}
//Post execution actions
#Override
protected void onPostExecute(Object response)
{
//Set task completed and notify the activity
completed = true;
_response = response;
notifyActivityTaskCompleted();
//Close the splash screen
if (pleaseWaitDialog != null)
{
pleaseWaitDialog.dismiss();
pleaseWaitDialog = null;
}
}
//Notify activity of async task completion
private void notifyActivityTaskCompleted()
{
if ( null != activity ) {
activity.onTaskCompleted(_response);
}
}
//for maintain attached the async task to the activity in phone states changes
//Sets the current activity to the async task
public void setActivity(MyActivity activity)
{
this.activity = activity;
if ( completed ) {
notifyActivityTaskCompleted();
}
}
}
}
Hope its help you
First of all you cannot set the adapter in the doInBackground
follow this design:
private class LoadMoreVehicals extends AsyncTask<Object, Integer, Object>
{
private ArrayList<Country> countries;
#Override
protected void onPreExecute() {
progressBar = ProgressDialog.show(RegistrationScreen.this, "","Loading...");
progressBar.setIndeterminate(true);
progressBar.setIndeterminateDrawable(getResources().getDrawable(R.anim.progressbar_handler));
super.onPreExecute();
}
#Override
protected Object doInBackground(Object... params) {
String countryUrl = ConstantURL.COUNTRY_URL;
countries = getCounty(countryUrl);
return null;
}
#Override
protected void onProgressUpdate(Integer... values) {
progressBar.getProgress();
}
#Override
protected void onPostExecute(Object result) {
countrySpinner.setAdapter(new MyCustomSpinnerAdapter(RegistrationScreen.this,R.layout.spinner_dropdown,countries));
progressBar.dismiss();
Log.e("Im in onPostExecute", "");
super.onPostExecute(result);
}
}