Changing adapter values in Gridview cause an exception

Question

I am using a Gridview to show some TextViews in the inside. I have created a clear button that set a new Adapter with empty ArrayList and it works fine. When I tried to perform the same operation in another place, an exception happen. I have tracked all my code till I have pointed out the statement that cause the problem.

Declairing the gridview at the first of the class

GridView gridView;

Got a reference in OnCreate method

gridView = (GridView) findViewById(R.id.gridView1);

Creating the adpater

String[] arrayEmpty = new String[] {"", "", "", "", "", "", "", "", ""};
ArrayList<String> list = new ArrayList<String>(Arrays.asList(arrayEmpty));
gridView.setAdapter(new ArrayAdapter<String>(this,R.layout.list_item,list));//list_item is acustomized layout for the TextView

What I am doing in Clear() method and works fine:

gridView.setAdapter(new ArrayAdapter<String>(MainActivity.this,R.layout.list_item,listEmpty));

What I am doing to set the values and DOES NOT WORK:

   ArrayList<String> gridList= new ArrayList<String>();

    for(int i=0;i<3;i++){
        for(int j=0;j<3;j++){
            gridList.add(String.valueOf(e[i][j].getValue()));
        }
    }
//The next statement cause an Exception..Why!!?
    gridView.setAdapter(new ArrayAdapter<String>(MainActivity.this,R.layout.list_item,gridList));

class solveTask extends AsyncTask<Object, Void, String> { 

    @Override
      protected void onPreExecute() {
        ProgressDialog pd = new ProgressDialog(MainActivity.this);
        pd.setProgress(ProgressDialog.STYLE_SPINNER);
        pd.setMessage("Solving, please wait a few seconds...");
        pd.setIndeterminate(true);
        pd.setCancelable(false);
        pd.show();
      }

    @Override
    protected String doInBackground(Object... parametros) {

        MainActivity.this.runOnUiThread(new Runnable() {
          public void run() {
             fillSudoku();
             solve();
          }
       });
       return null; 
    }


        @Override
        protected void onPostExecute(String result)
        {    //update progressDialog here
            pd.dismiss();
        }
    }

Some of the Log:

04-27 10:24:04.556: W/dalvikvm(7823): threadid=9: thread exiting with uncaught exception (group=0x40015560) 04-27 10:24:04.586: E/AndroidRuntime(7823): FATAL EXCEPTION: AsyncTask #1 04-27 10:24:04.586: E/AndroidRuntime(7823): java.lang.RuntimeException: An error occured while executing doInBackground() 04-27 10:24:04.586: E/AndroidRuntime(7823): at android.os.AsyncTask$3.done(AsyncTask.java:200) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.FutureTask.setException(FutureTask.java:125) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.FutureTask.run(FutureTask.java:138) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.lang.Thread.run(Thread.java:1019) 04-27 10:24:04.586: E/AndroidRuntime(7823): Caused by: java.lang.UnsupportedOperationException: removeAllViews() is not supported in AdapterView 04-27 10:24:04.586: E/AndroidRuntime(7823): at android.widget.AdapterView.removeAllViews(AdapterView.java:511) 04-27 10:24:04.586: E/AndroidRuntime(7823): at com.etaworx.thesudokusolver.MainActivity.printSudoku(MainActivity.java:481) 04-27 10:24:04.586: E/AndroidRuntime(7823): at com.etaworx.thesudokusolver.MainActivity.solve(MainActivity.java:579) 04-27 10:24:04.586: E/AndroidRuntime(7823): at com.etaworx.thesudokusolver.MainActivity$solveTask.doInBackground(MainActivity.java:625) 04-27 10:24:04.586: E/AndroidRuntime(7823): at com.etaworx.thesudokusolver.MainActivity$solveTask.doInBackground(MainActivity.java:1) 04-27 10:24:04.586: E/AndroidRuntime(7823): at android.os.AsyncTask$2.call(AsyncTask.java:185) 04-27 10:24:04.586: E/AndroidRuntime(7823): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306) 04-27 10:24:04.586: E/AndroidRuntime(7823): ... 4 more 04-27 10:24:09.849: E/WindowManager(7823): Activity com.etaworx.thesudokusolver.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4054e258 that was originally added here 04-27 10:24:09.849: E/WindowManager(7823): android.view.WindowLeaked: Activity com.etaworx.thesudokusolver.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@4054e258 that was originally added here 04-27 10:24:09.849: E/WindowManager(7823): at android.view.ViewRoot.(ViewRoot.java:258) 04-27 10:24:09.849: E/WindowManager(7823): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148) 04-27 10:24:09.849: E/WindowManager(7823): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91) 04-27 10:24:09.849: E/WindowManager(7823): at android.view.Window$LocalWindowManager.addView(Window.java:424) 04-27 10:24:09.849: E/WindowManager(7823): at android.app.Dialog.show(Dialog.java:241) 04-27 10:24:09.849: E/WindowManager(7823): at com.etaworx.thesudokusolver.MainActivity.showLoading(MainActivity.java:570) 04-27 10:24:09.849: E/WindowManager(7823): at com.etaworx.thesudokusolver.MainActivity$2.onClick(MainActivity.java:77) 04-27 10:24:09.849: E/WindowManager(7823): at android.view.View.performClick(View.java:2485) 04-27 10:24:09.849: E/WindowManager(7823): at android.view.View$PerformClick.run(View.java:9080) 04-27 10:24:09.849: E/WindowManager(7823): at android.os.Handler.handleCallback(Handler.java:587) 04-27 10:24:09.849: E/WindowManager(7823): at android.os.Handler.dispatchMessage(Handler.java:92) 04-27 10:24:09.849: E/WindowManager(7823): at android.os.Looper.loop(Looper.java:123) 04-27 10:24:09.849: E/WindowManager(7823): at android.app.ActivityThread.main(ActivityThread.java:3683) 04-27 10:24:09.849: E/WindowManager(7823): at java.lang.reflect.Method.invokeNative(Native Method) 04-27 10:24:09.849: E/WindowManager(7823): at java.lang.reflect.Method.invoke(Method.java:507) 04-27 10:24:09.849: E/WindowManager(7823): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 04-27 10:24:09.849: E/WindowManager(7823): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 04-27 10:24:09.849: E/WindowManager(7823): at dalvik.system.NativeStart.main(Native Method)

The LogCat output you get, it will contain a description of the exception. Assuming you use eclipse, there will be a lot of red colored text in your DDMS view/ the logcat window. — fweigl, May 03 '13 at 12:12
I have tracked the code till this statement...this is the one that makes the error @Ascorbin — Sami Eltamawy, May 03 '13 at 12:20
it shows you're using AsyncTask in your code,post that code also. that will show where is the problem. — RajaReddy PolamReddy, May 03 '13 at 12:41
@RajaReddyPolamReddy .. The problem exactly in the sentence of setting the adapter "gridView.setAdapter(arrAdapter);" .. but I will post the code of AsyncTask now — Sami Eltamawy, May 03 '13 at 12:42

RajaReddy PolamReddy · Accepted Answer · 2013-05-03T13:00:55.107

1

I think solve(); function running on main thread, doinbackground() running on background thread. change your solve() function like this

@Override
protected String doInBackground(Object... parametros) {
   this.runOnUiThread(new Runnable() {
      public void run() {
         solve();
      }
   });
   return null; 
}

edited May 03 '13 at 13:00

answered May 03 '13 at 12:55

RajaReddy PolamReddy

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Should I replace the statement Solve with your code? I think you are right because some parameters that was declaired in the main thread are null inside solve();...What this code do exactly? – Sami Eltamawy May 03 '13 at 12:58
1

yes change code in your doinbackground . look at my answer now. – RajaReddy PolamReddy May 03 '13 at 13:01
But, here is a problem. I was calling AsyncTask to be able to show the ProgressDialog but, now after making solve() works in the UIThread the progressDialog is disappeared..what should I do? – Sami Eltamawy May 03 '13 at 13:10
I am first, Calling a method to show the ProgressDialog in the mainThread, then invoke the solveTask().execute(); and dismiss it in the postExecution() – Sami Eltamawy May 03 '13 at 13:15
show the ProgressDialog in preExecution() of asynctask(). adn hide in postExecution() – RajaReddy PolamReddy May 03 '13 at 13:18
I did what you told me but did not happened. I have edited the above code of the onPreExecution to show you. – Sami Eltamawy May 03 '13 at 13:23
your changes are ok that have to work, are you getting any exceptions or what is the problem now. – RajaReddy PolamReddy May 03 '13 at 13:25
The progressDialog did not show while excecution and instantly showed up after execution and disappeared again – Sami Eltamawy May 03 '13 at 13:28

score 1 · Answer 2 · edited May 23 '17 at 11:43

AsyncTask

onPreExecute - invoked on UI thread , show progressDialog here
doInBackground() - invoked immediately after onPreExecute. Normally starts new thread and perform the long time operations here like web hit
onPostExecute() - invoked immediately after background thread execution in UI thread, dismiss progressDialog here

so avoid performing on UI thread in doInBackground(). Link

Your logs showing that exception on removeAllViews on AdatpterView please check for this exception and the below links may useful for you

Link1, Link2

Changing adapter values in Gridview cause an exception

2 Answers2