Android AsyncTask的简单Demo

package com.samir; import android.app.Activity; import android.app.AlertDialog; import android.app.Dialog; import android.content.DialogInterface; import android.os.AsyncTask; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.widget.Button; import android.widget.ProgressBar; import android.widget.TextView; public class MainActivity extends Activity { Button btnStart; MyTask objMyTask; private static final int SLEEP_TIME=((60*1000)/100); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btnStart = (Button) findViewById(R.id.btnstart); btnStart.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { objMyTask = new MyTask(); objMyTask.execute(); } }); } class MyTask extends AsyncTask<Void, Integer, Void> { Dialog dialog; ProgressBar progressBar; TextView tvLoading,tvPer; Button btnCancel; @Override protected void onPreExecute() { super.onPreExecute(); dialog = new Dialog(MainActivity.this); dialog.setCancelable(false); dialog.requestWindowFeature(Window.FEATURE_NO_TITLE); dialog.setContentView(R.layout.progressdialog); progressBar = (ProgressBar) dialog.findViewById(R.id.progressBar1); tvLoading = (TextView) dialog.findViewById(R.id.tv1); tvPer = (TextView) dialog.findViewById(R.id.tvper); btnCancel = (Button) dialog.findViewById(R.id.btncancel); btnCancel.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { objMyTask.cancel(true); dialog.dismiss(); } }); dialog.show(); } @Override protected Void doInBackground(Void... params) { for (int i = 1; i <100; i++) { if (isCancelled()) { break; } else { System.out.println(i); publishProgress(i); try { Thread.sleep(SLEEP_TIME); } catch (InterruptedException e) { e.printStackTrace(); } } } return null; } @Override protected void onProgressUpdate(Integer... values) { super.onProgressUpdate(values); progressBar.setProgress(values[0]); tvLoading.setText("Loading... " + values[0] + " %"); tvPer.setText(values[0]+" %"); } @Override protected void onPostExecute(Void result) { super.onPostExecute(result); dialog.dismiss(); AlertDialog alert = new AlertDialog.Builder(MainActivity.this) .create(); alert.setTitle("Completed!!!"); alert.setMessage("Your Task is Completed SuccessFully!!!"); alert.setButton("Dismiss", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); alert.show(); } } }