http://mobileorchard.com/android-app-developmentthreading-part-2-async-tasks/
package com.powenko;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.SystemClock;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
public class Tutorial_Dialog_AsyncTasksActivity extends Activity {
private ProgressBar progress;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
progress = (ProgressBar)findViewById(R.id.progress);
Button ImageView01 = (Button)findViewById(R.id.btn);
ImageView01.setOnClickListener(mCorkyListener);
Button ImageView02 = (Button)findViewById(R.id.btnCancel);
ImageView02.setOnClickListener(mCorkyListener);
}
private OnClickListener mCorkyListener =new OnClickListener() {
@Override
public void onClick(View v) {
ProgressTask task=new ProgressTask();
switch(v.getId()){
case R.id.btn:
task.execute(10);
break;
case R.id.btnCancel:
task.cancel(true);
break;
}
}
};
///////////////////////////////////////////////////
class ProgressTask extends AsyncTask<Integer, Integer, Void>{
@Override
protected void onPreExecute() {
// initialize the progress bar
// set maximum progress to 100.
progress.setMax(100);
}
@Override
protected void onCancelled() {
// stop the progress
progress.setMax(0);
}
@Override
protected Void doInBackground(Integer... params) {
// get the initial starting value
int start=params[0];
// increment the progress
for(int i=start;i<=100;i+=5){
try {
boolean cancelled=isCancelled();
//if async task is not cancelled, update the progress
if(!cancelled){
publishProgress(i);
SystemClock.sleep(100);
}
} catch (Exception e) {
Log.e("Error", e.toString());
}
}
return null;
}
@Override
protected void onProgressUpdate(Integer... values) {
// increment progress bar by progress value
progress.setProgress(values[0]);
}
@Override
protected void onPostExecute(Void result) {
// async task finished
Log.v("Progress", "Finished");
}
}
}
res\layout\main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="@+id/btn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Show Progress"
></Button>
<ProgressBar
android:id="@+id/progress"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
style="?android:attr/progressBarStyleHorizontal"
></ProgressBar>
<Button
android:id="@+id/btnCancel"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Cancel"
></Button>
</LinearLayout>