I display an Alertbox with ok or cancel.
I want to implement an asynch task on the press of OK. Havent done asynch and been struggling with it for awhile. I dont understand where the asych class goes also. Does it go outside the method that is being executed or outside of it? Current code as follows:
private abstract class DoAsynchTask extends AsyncTask<Void,Void,Void>
{
protected void doInBackground()
{
Drawable drawable= getImage(imageSelect);
MakeWallPaper(drawable,1);
}
/* protected void onProgressUpdate(Integer... progress)
{
setProgress(progress[0]);
}*/
protected void onPostExecute()
{
Toast.makeText(getApplicationContext(), "Wallpaper Saved.",Toast.LENGTH_LONG).show();
AlertDialogProcessing=0;
}
}
public void getWallpaper(final View v)
{
if(AlertDialogProcessing==0)
{
final String title="Set Image to Wallpaper";
final String message="Press OK to set as Wallpaper or CANCEL.\nWait after pushing OK.";
final String ok="OK";
final String cancel="CANCEL";
final AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
alertbox.setCancelable(true);
alertbox.setIcon(android.R.drawable.ic_dialog_alert);
alertbox.setTitle(title);
alertbox.setMessage(message);
alertbox.setNegativeButton(cancel, null);
final AlertDialog dlg = alertbox.create();
alertbox.setPositiveButton(ok,new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dlg, int which)
{
DoAsynchTask.execute(null,null,null); //<<<<Wrong
dlg.dismiss();
Vibrate(ClickVibrate);
}
});
alertbox.setNegativeButton(cancel,new DialogInterface.OnClickListener(){ public void onClick(DialogInterface arg0, int arg1){AlertDialogProcessing=0;
Vibrate(ClickVibrate); } });
alertbox.show();
}
}
There's a couple problems in the code.
1) First of all, the compiler is probably giving you this message:
The type MyActivity.DoAsynchTask must implement the inherited abstract
method
AsyncTask.doInBackground(Void...) MyActivity.java
If you look closely at the error message, you'll realize that what you defined was this:
protected void doInBackground() {
which is not what is needed. Even though it might seem silly, when your AsyncTask subclass takes Void as the generic parameter types, that means that doInBackground() must look like this:
protected Void doInBackground(Void... arg0) {
The compiler complains because you haven't implemented that (exact) method. When you inherit from an abstract class, and fail to implement all of its required/abstract method(s), then you can only get it to compile by marking the subclass as abstract, too. But, that's not really what you want.
So, just change your code to (remove abstract from your class):
private class DoAsynchTask extends AsyncTask<Void,Void,Void>
and
protected Void doInBackground(Void... arg0) {
{
Drawable drawable= getImage(imageSelect);
MakeWallPaper(drawable,1);
return null;
}
2) And the second problem, as others have pointed out, is that you must start your task with:
new DoAsynchTask().execute();
not
DoAsynchTask.execute(null,null,null);
Your code would only be correct if execute() was a static method in AsyncTask, which it's not. In order to invoke the non-static execute() method, you first need a new instance of the DoAsynchTask class. Finally, the null, null, null parameter list is also not necessary, although I don't think it will cause the code to fail either.
Since your doInBackground() does not specify any parameters, you should call DoAsynchTask.execute() without parameters.
Why is your class abstract? Normally an AsyncTask should be an inner class of the activity starting it. So create your dialog in the activity, and execute the AsyncTask when clicking on OK button, like you do.
//final working copy -Thanks ALL
public void getWallpaper(final View v)
{
Vibrate(ClickVibrate);
final class SetWallPaperAsynchTask extends AsyncTask<Void,Void,Void>
{
#Override
protected Void doInBackground(Void... arg0)
{
Drawable drawable= getImage(imageSelect);
MakeWallPaper(drawable,1);
return null;
}
#Override
protected void onPostExecute(Void result)
{Toast.makeText(getBaseContext(), "Wallpaper Saved.", Toast.LENGTH_LONG).show();
AlertDialogProcessing=0;
}
}
if(AlertDialogProcessing==0)
{
ProgressDialog progress;
final String title="Set Image to Wallpaper";
final String message="Press OK to set as Wallpaper or CANCEL.";
final String ok="OK";
final String cancel="CANCEL";
final AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
alertbox.setCancelable(true);
alertbox.setIcon(android.R.drawable.ic_dialog_alert);
alertbox.setTitle(title);
alertbox.setMessage(message);
alertbox.setNegativeButton(cancel, null);
final AlertDialog dlg = alertbox.create();
alertbox.setPositiveButton(ok,new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface arg0, int arg1)
{
new SetWallPaperAsynchTask().execute();
dlg.dismiss();
Vibrate(ClickVibrate);
}
});
alertbox.setNegativeButton(cancel,new DialogInterface.OnClickListener(){ public void onClick(DialogInterface arg0, int arg1){AlertDialogProcessing=0; Vibrate(ClickVibrate); } });
alertbox.show();
}
}
Related
I created this AsyncTask inner class and now I want to make it outer. Here is the code:
private class DownloadDataFromServer extends AsyncTask<String, Integer, String> {
ProgressDialog dialog;
boolean connErr = false;
boolean soErr = false;
#Override
protected void onPreExecute() {
dialog = new ProgressDialog(HomePage.this); !!!!PROBLEM!!!!
dialog.setIndeterminate(false);
dialog.setMax(100);
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dialog.setCancelable(false);
dialog.setTitle("Download");
dialog.setMessage("Updating...");
dialog.show();
super.onPreExecute();
}
#Override
protected String doInBackground(String... urls) {
// do something
}
protected void onProgressUpdate(Integer... progress) {
// Update the progress
dialog.setProgress(progress[0]);
}
#Override
protected void onPostExecute(String result) {
if (connErr || soErr) {
String msg = "Bad connection";
AlertDialog.Builder builder;
builder = new AlertDialog.Builder(HomePage.this); !!!!PROBLEM!!!!
builder.setCancelable(false);
builder.setTitle("Connection timeout");
builder.setMessage(msg);
builder.setPositiveButton("Retry", new DialogInterface.OnClickListener(){
#Override
public void onClick(DialogInterface dialog, int which)
{
dialog.dismiss();
new DownloadDataFromServer().execute(new String[] { "http://www.example.com" });
}
});
builder.setNegativeButton("Exit", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
finish(); !!!!PROBLEM!!!!
}
});
AlertDialog dialog = builder.create();
dialog.show();
} else {
if (Integer.parseInt(result) <= 0) {
Toast.makeText(getBaseContext(), "Error!", Toast.LENGTH_SHORT).show(); !!!!PROBLEM!!!!
} else {
Toast.makeText(getBaseContext(), "OK!", Toast.LENGTH_SHORT).show(); !!!!PROBLEM!!!!
}
}
dialog.dismiss();
}
}
Please note "!!!!PROBLEM!!!!" strings in the above code: there are all the errors that I get. I tried to apply some workarounds but finally I could not make it working. In addition I also have to use
private Database db = new Database(this);
but I do not know what to put in place of "this". Please help me to convert this inner class in the right way.
You should make one argument constructor to DownloadDataFromServer class and pass Context as argument like
Context mCon;
public DownloadDataFromServer(Context con){
this.mCon=con;
}
and used this mCon context to anywhere in your DownloadDataFromServer like so
builder = new AlertDialog.Builder(mCon);
and at last called DownloadDataFromServer from any Activity like
new DownloadDataFromServer(your_Activity.this).execute(......);
Make yout DownloadDataFromServer have a constructor accepting HomeScreen, save the home screen in a field in the constructor and then use that field everywhere instead of HomeScreen.this.
You may have to make some of your private fields of HomeScreen public (or provide accessors) because of that.
You do not want to do all that though, what's the advantage?
I have a splash screen that runs an asyncTask that downloads data from an API. On that task's OnPostExecute I run the next asyncTask to send stored emails. Once that is complete I need an AlertDialog to popup with an ok button so the user knows the downloads are complete. I used this SO question to get as far as I have:
Android AlertDialog inside AsyncTask
Now I'm getting a NullPointerException when I attempt to add properties to the dialog:
public class JSONParser extends AsyncTask<String, String, JSONObject> {
Context c;
public JSONParser(int api,Context c) {
this.api= api;
this.c = c;
}
...
protected void onPostExecute(JSONObject result) {
JSONObject output = new JSONEmailParser(c).executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, new String[] {null,null,null,null}).get();
}
}
public class JSONEmailParser extends AsyncTask<String, String, JSONObject> {
Context c;
AlertDialog.Builder builder;
public JSONEmailParser(Context c){
this.c = c;
}
protected void onPreExecute(int api){
builder = new AlertDialog.Builder(SplashScreen.this);
}
...
protected void onPostExecute(JSONObject result) {
setLastUpdate();
builder.setTitle("Sales Toolkit");
builder.setCancelable(false);
builder.setMessage("Download Complete");
builder.setPositiveButton("Continue", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
dialog.dismiss();
endSplash();
}
});
builder.show();
}
}
The error is coming up on builder.setTitle("Sales Toolkit");
AsyncTask#onPreExecute() doesn't take an int argument. Since your method has the wrong signature, it is likely never being called, and therefore builder is never set. This is a classic example of why you should use #Override annotations.
Do not use a .get() to execute an AsyncTask as it will not be async anymore. And onPreExecute will not be called?
It seems like the onPreExecute() method is not being called. If you don't really need to use the builder anywhere before the onPostExecute() method, I would suggest just moving
builder = new AlertDialog.Builder(SplashScreen.this);
into the onPostExecute() method.
I am creating an application class to perform some version checks during application launch. Below is my class.
public class MyApp extends Application {
public MyApp() {
}
#Override
public void onCreate() {
super.onCreate();
new checkVersionTask().execute(getApplicationContext)
}
private class checkVersionTask extends AsyncTask<Context, Integer, Long> {
#Override
protected Long doInBackground(Context... contexts) {
TODO—version check code
}
protected void onPostExecute(Long result) {
AlertDialog alertDialog;
alertDialog = new AlertDialog.Builder(MyApp.this).create();
alertDialog.setMessage(("A new version of app is available. Would you like to upgrade now?"));
alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, getResources().getString(R.string.Button_Text_Yes), new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int which) {
Uri uri = Uri.parse("update URL");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
});
alertDialog.setButton(AlertDialog.BUTTON_NEGATIVE,getResources().getString(R.string.Button_Text_No), new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
alertDialog.show();
}
}
catch(Exception e){
Toast.makeText(getApplicationContext(), "ERROR:"+e.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
here alertDialog.show is throwing error
android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
As I understand this is because the context is not available. In the line
alertDialog = new AlertDialog.Builder(MyApp.this).create();
I tried getApplicationContext() instead of MyApp.this, still the same issue.
Can anyone suggest what's going wrong here. All the Toast statement are working fine.
You can not create a dialog within an application class since, the Dialog should be attached to a window, an Application is not UI class and has no window, so it can't show the dialog.
you can solve it by creating an activity which will show the dialog (you can pass the data as an extra with the intent), and when the data is ready fire and intent and show the dialog
There are two options for giving your AsyncTask the proper context:
1) Use getBaseContext()
I'm not positive if this will work, it seems to function in some situations rather than others.
2) If THAT doesn't work, you'll need to set up a constructor method for your checkVersionTask, as follows.
Context context; //member variable of the checkVersionTask class
public checkVersionTask(Context c) {
this.context = c;
}
Then, when you call the task in your onCreate method, or anywhere in your activity class for that matter, call it like so
new checkVersionTask(MyApp.this).execute();
Whenever you need to access context within the checkVersionTask, just say, for example
alertDialog = new AlertDialog.Builder(context).create();
I am getting weird behavior when executing AsyncTask from AlertDialog. I need some suggestion/workaround to fix it. I am stuck at this point.
When I execute AsyncTask from AlertDialog, it is not calling onPostExecute. It call doInBackground, but after finish, it doesn't call onPostExecute. I want AsyncTask to get executed on the basis of AlertDialog's button press value.
Here is the function that creates AlertDialog and executes AsyncTask:
private void processDownloadChoosen(String msg, int __position){
final AlertDialog.Builder alertBox = new AlertDialog.Builder(new ContextThemeWrapper(ShivaniMP3Activity.this, android.R.style.Theme_Dialog));
final int position = __position;
alertBox.setMessage(msg);
alertBox.setCancelable(false)
.setPositiveButton("Download", new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog,int id){
dialog.dismiss();
String downloadURL = entries.get(position);
AsyncTaskDownload atd = new AsyncTaskDownload(downloadURL);
if((downloadURL != null) &&(downloadURL != "")){
EnglishMP3Activity.totalDownloads++;
if(downloadWindow == null){
downloadWindow = new PopupWindow(downloadPopupLayout, LayoutParams.MATCH_PARENT,LayoutParams.WRAP_CONTENT, true);
downloadWindow.showAtLocation(downloadPopupLayout, Gravity.CENTER, 0, 0);
}
atd.execute();
}
}
}).setNegativeButton("Listen", new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog,int id){
dialog.dismiss();
String downloadURL = entries.get(position).replace("%20", " ");
emp = new EasyMediaPlayer(mp3PopupLayout,buttonPlayPause,seekBarProgress,tv_mp3,downloadURL);
emp.startPlayingMP3();
}
}).show();
}
And I am calling this function from listview's on item click:
//lv is listview
lv.setOnItemClickListener(new AdapterView.OnItemClickListener(){
public void onItemClick(AdapterView<?> p, View v, int position, long id) {
processDownloadChoosen("Do you want to Listen or Download this file ?",position);
}
});
My AsyncTask definition look like:
public class AsyncTaskDownload extends AsyncTask<Void, String, Void> {
//
protected void onPreExecute(){
pBar1.setVisibility(View.INVISIBLE);
//
}
protected Void doInBackground(Void... vd){
try{
//do something
}
catch(Exception e){
//do somting
}
return null;
}
protected void onProgressUpdate(String... msg) {
//do smething
}
protected void onPostExecute(Void in){
cancelDownloadButton.setVisibility(View.GONE);
//do smtthing
}
}
PLEASE NOTE: When I execute AsyncTask directly from ListView's on item click function, all works well. But while calling from AlertDialog, it doesn't call onPostExecute.
Any help to resolve/workaround for this is appreciated.. Advance Thanks
Try using a handler/Runnable such that in the alertDialog's onPositiveClick callback you do
Handler mHandler;
prtected void onCreate(Bundle sis) {
//other code
this.mHandler = new Handler();
}
//In your DialogInterface.OnClickListener
mHandler.post(new Runnable() {
#Override
public void run() {
//Init and launch your asynctask here
}
});
The reason this is not working is that an AsyncTask must be invoked on the UI thread and im pretty sure that invoking on the positive button callback is not linked directly with the activities context (given that the task works from the ListView's onItemClick callback)
After going through several posts, it looks like AsyncTask doesn't work properly from AlertDialog.
So I achieved this by "fooling" Android. Noe I am doing everything inside doInBackground function and also getting the feel as if preexecute/postexecute is getting called.
Below is what i did:
1) Removed onPreExecute() and onProgressUpdate() from AsyncTask.
2) define doInBackground something like:
protected Void doInBackground(Void... vd){
publishProgress("I_AM_STARTED");
//Other Work
publishProgress("I_AM_DONE");
}
3) define onProgressUpdate something like:
protected void onProgressUpdate(String... msg) {
if(msg[0].equals("I_AM_STARTED")){
//code for onPreExecute
}
else if(msg[0].equals("I_AM_DONE")){
//code for onPostExecute
}
else{
//normal code
}
}
Hope this may be helpful for someone who got stuck like me. :-)
I'm using a AsyncTask
I use parent to create the intent no errors.
The line to creat a dialog gives a
parent cannot be resolved to a ye.
new parent.AlertDialog.Builder(this)
The error I get is that parent does not exist, but I use parent in the same methed to call the intent
code block
private class SendTextOperation extends AsyncTask {
#Override
protected void onPreExecute() {
//Update UI here
}
#Override
protected String doInBackground(String... params) {
// Talk to server here to avoid Ui hanging
rt=TalkToServer("http://besttechsolutions.biz/projects/bookclub/login.php");
return(rt);
}
#Override
protected void onPostExecute(String result) {
if (rt.contains("ok"))
{
Intent i = new Intent(parent, cChat.class);
startActivity(i);
}
else
{
new parent.AlertDialog.Builder(this)
.setTitle("Game Over")
.setMessage("Your time is up, You saved "
+" Million more people!!")
.setNeutralButton("Try Again",new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dlg, int i)
{
}} ).show();
}
}
}
For showing AlertDialog from non Activity you will need to pass Current Activity Context to non Activity class in your case to SendTextOperation class.
Create an Constructor for SendTextOperation as :
public class SendTextOperation extends AsyncTask<String,Void,String>{
Context context;
public SendTextOperation(Context context) {
this.context = context;
}
#Override
protected void onPreExecute() {
//Update UI here
}
#Override
protected String doInBackground(String... params) {
// Talk to server here to avoid Ui hanging
rt=TalkToServer("http://besttechsolutions.biz/projects/bookclub/login.php");
return(rt);
}
#Override
protected void onPostExecute(String result) {
if (rt.contains("ok"))
{
Intent i = new Intent(context, cChat.class);
startActivity(i);
}
else
{
new context.AlertDialog.Builder(context)
.setTitle("Game Over")
.setMessage("Your time is up, You saved "
+" Million more people!!")
.setNeutralButton("Try Again",new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dlg, int i)
{
}} ).show();
}
}
}
and start SendTextOperation AsyncTask as :
SendTextOperation sendtxtasyncTask = new SendTextOperation(CurrentActivity.this);
sendtxtasyncTask.execute("");
Lets say you have that class declared inside a class named MyActivity
Then use instead of this, MyActivity.this when creating the Dialog.
It looks like you should be calling it like this:
final AlertDialog.Builder builder = new AlertDialog.Builder(_context);
builder.setMessage(_context.getString(R.string.error) + ": " + _errorMessage)
.setTitle(_context.getString(R.string.loginError))
.setIcon(android.R.drawable.ic_dialog_alert)
.setCancelable(true)
.setPositiveButton(_context.getString(R.string.ok), null);
final AlertDialog alert = builder.create();
alert.show();
(My own sample code)
It looks like your error is trying to do parent.AlertDialog.Builder(this), where you need to use new AlertDialog.Builder(parent), if parent is your context.