How to use AsyncTask correctly in Android [closed]

Question

I don't want to pass any arguments to doInBackground method of the AsyncTask.

So what should be the code like?

Answer 1

import android.app.Activity; import android.app.ProgressDialog; import android.os.AsyncTask; import android.os.Bundle;  public class AsyncExample extends Activity{   private String url="http://www.google.co.in";  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState); }   @Override protected void onResume() {     // TODO Auto-generated method stub     super.onResume();      new AsyncCaller().execute();  }  private class AsyncCaller extends AsyncTask<Void, Void, Void> {     ProgressDialog pdLoading = new ProgressDialog(AsyncExample.this);      @Override     protected void onPreExecute() {         super.onPreExecute();          //this method will be running on UI thread         pdLoading.setMessage("\tLoading...");         pdLoading.show();     }     @Override     protected Void doInBackground(Void... params) {          //this method will be running on background thread so don't update UI frome here         //do your long running http tasks here,you dont want to pass argument and u can access the parent class' variable url over here           return null;     }      @Override     protected void onPostExecute(Void result) {         super.onPostExecute(result);          //this method will be running on UI thread          pdLoading.dismiss();     }      } } 

Answer 2

According to AsyncTask, its

 AsyncTask<Params, Progress, Result> 

• Params, the type of the parameters sent to the task upon execution.
• Progress, the type of the progress units published during the background computation.
• Result, the type of the result of the background computation.

So if you want to pass void in doInBackground just pass void in place of Params.

Example code:

class DownloadLink extends AsyncTask<Void, Void, Void> {           @Override         protected Void doInBackground(Void... params) {             // TODO Auto-generated method stub              //Do Your stuff here..             return null;         }     } 

And call it as:

 new DownloadLink().execute();