MainActivity.java

package net.sgoliver.android.asynctask;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.DialogInterface.OnCancelListener;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.Toast;

public class MainActivity extends Activity {
	
	private Button btnSinHilos;
	private Button btnHilo;
	private Button btnAsyncTask;
	private Button btnCancelar;
	private Button btnAsyncDialog;
	private ProgressBar pbarProgreso;
	
	private ProgressDialog pDialog;
	
	private MiTareaAsincrona tarea1;
	private MiTareaAsincronaDialog tarea2;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		btnSinHilos = (Button)findViewById(R.id.btnSinHilos);
        btnHilo = (Button)findViewById(R.id.btnHilo);
        btnAsyncTask = (Button)findViewById(R.id.btnAsyncTask);
        btnCancelar = (Button)findViewById(R.id.btnCancelar);
        btnAsyncDialog = (Button)findViewById(R.id.btnAsyncDialog);
        pbarProgreso = (ProgressBar)findViewById(R.id.pbarProgreso);
        
        btnSinHilos.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				pbarProgreso.setMax(100);
				pbarProgreso.setProgress(0);
				for(int i=1; i<=10; i++) {
					tareaLarga();
					pbarProgreso.incrementProgressBy(10);
				}
				Toast.makeText(MainActivity.this, "Tarea finalizada!", Toast.LENGTH_SHORT).show();
			}
		});
        
        btnHilo.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				new Thread(new Runnable() {
				    public void run() {
				    	pbarProgreso.post(new Runnable() {
				    		public void run() {
				    			pbarProgreso.setProgress(0);
				    		}
				    	});
				    	
				    	for(int i=1; i<=10; i++) {
				    		
							tareaLarga();
							
							pbarProgreso.post(new Runnable() {
					    		public void run() {
					    			pbarProgreso.incrementProgressBy(10);
					    		}
					    	});
						}
				    	
				    	runOnUiThread(new Runnable() {
				    	    public void run() {
				    	        Toast.makeText(MainActivity.this, "Tarea finalizada!", Toast.LENGTH_SHORT).show();
				    	    }
				    	});
				    }
				}).start();
			}
		});
        
        btnAsyncTask.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				tarea1 = new MiTareaAsincrona();
				tarea1.execute();
			}
			
		});
        
        btnCancelar.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				tarea1.cancel(true);
			}
		});
        
        btnAsyncDialog.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				
				pDialog = new ProgressDialog(MainActivity.this);
				pDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
				pDialog.setMessage("Procesando...");
				pDialog.setCancelable(true);
				pDialog.setMax(100);
				
				tarea2 = new MiTareaAsincronaDialog();
				tarea2.execute();
			}
		});
	}
	
	private void tareaLarga()
    {
    	try { 
    		Thread.sleep(1000); 
    	} catch(InterruptedException e) {}
    }

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	private class MiTareaAsincrona extends AsyncTask<Void, Integer, Boolean> {
    	
    	@Override
    	protected Boolean doInBackground(Void... params) {
    		
    		for(int i=1; i<=10; i++) {
				tareaLarga();
				
				publishProgress(i*10);
				
				if(isCancelled())
					break;
			}
    		
    		return true;
    	}
    	
    	@Override
    	protected void onProgressUpdate(Integer... values) {
    		int progreso = values[0].intValue();
    		
    		pbarProgreso.setProgress(progreso);
    	}
    	
    	@Override
    	protected void onPreExecute() {
    		pbarProgreso.setMax(100);
    		pbarProgreso.setProgress(0);
    	}
    	
    	@Override
    	protected void onPostExecute(Boolean result) {
    		if(result)
    			Toast.makeText(MainActivity.this, "Tarea finalizada!", Toast.LENGTH_SHORT).show();
    	}
    	
    	@Override
    	protected void onCancelled() {
    		Toast.makeText(MainActivity.this, "Tarea cancelada!", Toast.LENGTH_SHORT).show();
    	}
    }
    
    private class MiTareaAsincronaDialog extends AsyncTask<Void, Integer, Boolean> {
    	
    	@Override
    	protected Boolean doInBackground(Void... params) {
    		
    		for(int i=1; i<=10; i++) {
				tareaLarga();
				
				publishProgress(i*10);
				
				if(isCancelled())
					break;
			}
    		
    		return true;
    	}
    	
    	@Override
    	protected void onProgressUpdate(Integer... values) {
    		int progreso = values[0].intValue();
    		
    		pDialog.setProgress(progreso);
    	}
    	
    	@Override
    	protected void onPreExecute() {
    		
    		pDialog.setOnCancelListener(new OnCancelListener() {
				@Override
				public void onCancel(DialogInterface dialog) {
					MiTareaAsincronaDialog.this.cancel(true);
				}
			});
    		
    		pDialog.setProgress(0);
    		pDialog.show();
    	}
    	
    	@Override
    	protected void onPostExecute(Boolean result) {
    		if(result)
    		{
    			pDialog.dismiss();
    			Toast.makeText(MainActivity.this, "Tarea finalizada!", Toast.LENGTH_SHORT).show();
    		}
    	}
    	
    	@Override
    	protected void onCancelled() {
    		Toast.makeText(MainActivity.this, "Tarea cancelada!", Toast.LENGTH_SHORT).show();
    	}
    }
}