Asynctask have 4 override methods onPreExecute()
, doInBackground()
, onProgressUpdate()
, onPostExecute()
except onProgressUpdate
all are working.
What should I do so that onProgressUpdate() should work.
Can anybody please briefly explain me what's the use of onProgressUpdate()
, what should write within this?
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35
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`progressDialog.setIndeterminate(false);` if you have given `true` – Pratik Butani Oct 21 '13 at 11:11
3 Answers
65
onProgressUpdate()
is used to operate progress of asynchronous operations via this method. Note the param with datatype Integer
. This corresponds to the second parameter in the class definition. This callback can be triggered from within the body of the doInBackground()
method by calling publishProgress()
.
Example
import android.app.Activity;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class AsyncTaskExample extends Activity {
protected TextView _percentField;
protected Button _cancelButton;
protected InitTask _initTask;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
_percentField = (TextView) findViewById(R.id.percent_field);
_cancelButton = (Button) findViewById(R.id.cancel_button);
_cancelButton.setOnClickListener(new CancelButtonListener());
_initTask = new InitTask();
_initTask.execute(this);
}
protected class CancelButtonListener implements View.OnClickListener {
public void onClick(View v) {
_initTask.cancel(true);
}
}
/**
* sub-class of AsyncTask
*/
protected class InitTask extends AsyncTask<Context, Integer, String> {
// -- run intensive processes here
// -- notice that the datatype of the first param in the class definition matches the param passed to this
// method
// -- and that the datatype of the last param in the class definition matches the return type of this method
@Override
protected String doInBackground(Context... params) {
// -- on every iteration
// -- runs a while loop that causes the thread to sleep for 50 milliseconds
// -- publishes the progress - calls the onProgressUpdate handler defined below
// -- and increments the counter variable i by one
int i = 0;
while (i <= 50) {
try {
Thread.sleep(50);
publishProgress(i);
i++;
}
catch (Exception e) {
Log.i("makemachine", e.getMessage());
}
}
return "COMPLETE!";
}
// -- gets called just before thread begins
@Override
protected void onPreExecute() {
Log.i("makemachine", "onPreExecute()");
super.onPreExecute();
}
// -- called from the publish progress
// -- notice that the datatype of the second param gets passed to this method
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
Log.i("makemachine", "onProgressUpdate(): " + String.valueOf(values[0]));
_percentField.setText((values[0] * 2) + "%");
_percentField.setTextSize(values[0]);
}
// -- called if the cancel button is pressed
@Override
protected void onCancelled() {
super.onCancelled();
Log.i("makemachine", "onCancelled()");
_percentField.setText("Cancelled!");
_percentField.setTextColor(0xFFFF0000);
}
// -- called as soon as doInBackground method completes
// -- notice that the third param gets passed to this method
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Log.i("makemachine", "onPostExecute(): " + result);
_percentField.setText(result);
_percentField.setTextColor(0xFF69adea);
_cancelButton.setVisibility(View.INVISIBLE);
}
}
}

BenMorel
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Sunil Kumar Sahoo
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1I wanna for spaecific time the dilog should appear. If takes more time I want give an alert.then where i will give that? – Jyosna Jun 23 '11 at 07:43
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In onProgressUpdate(), super method not accepting Integer value as argument. It accepts only Void – Ragavendra M Nov 15 '17 at 11:00
4
onProgressUpdate runs on the UI thread after publishProgress is invoked. From AsyncTask documentation - your code should look something like this
private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {
protected Long doInBackground(URL... urls) {
int count = urls.length;
long totalSize = 0;
for (int i = 0; i < count; i++) {
totalSize += Downloader.downloadFile(urls[i]);
publishProgress((int) ((i / (float) count) * 100));
}
return totalSize;
}
protected void onProgressUpdate(Integer... progress) {
setProgressPercent(progress[0]);
}
protected void onPostExecute(Long result) {
showDialog("Downloaded " + result + " bytes");
}
}

Mojo Risin
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1
hey this might help you??
the progress bar will automatically disappear when you will get the response
User_AsyncTaskk extends AsyncTask
public class User_AsyncTask extends AsyncTask<String, String, String>
{
String response = "";
@Override
protected void onPreExecute()
{
try
{
if (progressDialog != null)
progressDialog.cancel();
}
catch (Exception e)
{
}
progressDialog = ProgressDialog.show(DisplayDetails.this, "", "Please wait...", true, true);
progressDialog.setCancelable(false);
progressDialog.show();
}
protected String doInBackground(String... params)
{
try
{
//Complete ur Code
Log.i("AUTO ", "response is : " + response);
return response;
}
catch (Exception e)
{
}
}
@Override
protected void onPostExecute(String s)
{
if (progressDialog != null) {
progressDialog.dismiss();
progressDialog = null;
}
try {
}
catch (Exception e)
{
}
}

Vaibhav Joshi
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