Question

My question is how to pass parameter to AsyncTask dynamically. How I do this?

 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.daily_download);

    SharedPreferences myPrefs = this.getSharedPreferences("myLogedPrefs",MODE_WORLD_READABLE);
    strBusinessUnit = myPrefs.getString("BusinessUnit", "");
    strExecutive = myPrefs.getString("Executive", "");
    strTerritoryCode = myPrefs.getString("TerritoryCode", "");

    tableListGrid = (GridView)findViewById(R.id.dailydownloadgrid);
    tableListGrid.setAdapter(new TableListImageAdapter(this));
    tableListGrid.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView parent, View v, int position,long id) {
            if (position == 0) {
                dailyDownTable = "LoadTarget";
                jsonFilter = "Target1";
                new DailyDownldAsyncTask().execute();
            }
        }
    });
}



    public class DailyDownldAsyncTask extends AsyncTask<Void, Integer, Void> {
        // private final ProgressDialog dialog = new ProgressDialog(DailyDownloadActivity.this);
         int myProgress;

        @Override
        protected void onPostExecute(Void result) {

            //if (this.dialog.isShowing()) {
            //  this.dialog.dismiss();
            //}
            //Toast.makeText(DailyDownloadActivity.this,"Download successfully",Toast.LENGTH_SHORT).show();

        }

      @Override
      protected void onPreExecute() {

         // this.dialog.setMessage("Downloading Table Data.......");
         // this.dialog.show();
         // myProgress = 0;
      }

      @Override
      protected Void doInBackground(Void... params) {
          new DownlaodTableActivity().loadDailyDownloadData(dailyDownTable,jsonFilter,strBusinessUnit, strBusinessUnit,strTerritoryCode);
       return null;
      }

      @Override
      protected void onProgressUpdate(Integer... values) {
         // dialog.setProgress(values[0]);
      }
 }

I commented ‘ProgressDialog ‘ & run the code also I got error
Here loadDailyDownloadDatadailyDownTable,jsonFilter,strBusinessUnit, strBusinessUnit,strTerritoryCode) method i want to pass parameter.

When I run this code I got error :

     08-19 09:22:15.521: ERROR/AndroidRuntime(457): FATAL EXCEPTION: AsyncTask #2
08-19 09:22:15.521: ERROR/AndroidRuntime(457): java.lang.RuntimeException: An error occured while executing doInBackground()
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at android.os.AsyncTask$3.done(AsyncTask.java:200)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.lang.Thread.run(Thread.java:1019)
08-19 09:22:15.521: ERROR/AndroidRuntime(457): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at android.os.Handler.<init>(Handler.java:121)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at android.app.Activity.<init>(Activity.java:680)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at com.xont.controller.syn.DownlaodTableActivity.<init>(DownlaodTableActivity.java:62)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at com.xont.controller.admin.DailyDownloadActivity$DailyDownldAsyncTask.doInBackground(DailyDownloadActivity.java:83)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at com.xont.controller.admin.DailyDownloadActivity$DailyDownldAsyncTask.doInBackground(DailyDownloadActivity.java:1)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
08-19 09:22:15.521: ERROR/AndroidRuntime(457):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)

Please help me ….

Thanks in advance

Answer 1

Seem you need to read the document for AsyncTask more first. http://developer.android.com/reference/android/os/AsyncTask.html

Crashing problem:

Keep in mind that doInBackground will be executed in background thread. The crashing problem you are seeing is that DownlaodTableActivity is instantiated inside a background thread, which is IMPOSSIBLE in Android framework. (Has nothing to do with parameters passing by the way) All activities must be instantiated in the main UI thread. The Looper.prepare() will be called if you have instantiated it in UI thread.

Solution: move loadDailyDownloadData to a different class that does not depend on DownlaodTableActivity. If you want to the UI to be updated in DownlaodTableActivity, do it in UI thread after you download the data.

Parameter passing:

strBusinessUnit = myPrefs.getString("BusinessUnit", "");
strExecutive = myPrefs.getString("Executive", "");
strTerritoryCode = myPrefs.getString("TerritoryCode", "");
... ...
new DailyDownldAsyncTask().execute(dailyDownTable, jsonFilter, strBusinessUnit, strExecutive, strTerritoryCode);
... ...

public class DailyDownldAsyncTask extends AsyncTask<String, Integer, Void> {
        // private final ProgressDialog dialog = new ProgressDialog(DailyDownloadActivity.this);
         int myProgress;

... ...

      @Override
      protected Void doInBackground(Void... params) { 
dailyDownloadData(params[0],params[1],params[2], params[3],params[4];
       return null;
      }
... ...
 }