CODEWITHSUNDEEP
androidasynchronousandroid-asynctask
brian
brian

Reputation: 6912

AsyncTask doesn't invoke onPostExecute()

I am writing an AsyncTask as below:

class Load extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... aurl) {
//do job seconds
//stop at here, and does not run onPostExecute
}
@Override
protected void onPostExecute(String unused) {
super.onPostExecute(unused);
wait = false;
new Load().execute();
}
}

And the other method as below:

public void click() {
new Load().execute();
while(wait) {
;
}
}

The wait is a global boolean value.

Upvotes: 1

Views: 3627

Answers (4)

Android
Android

Reputation: 1427

this is proppar way asynctask, you wont to use wait in any other method or sleep both are
use same normal method 

private class AsyncTask extends AsyncTask<Void, Void, Void> {
        ProgressDialog progressDialog;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();

        }

        @Override
        protected Void doInBackground(Void... params) {

        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            progressDialog.dismiss();

        }
    }

Upvotes: 3

kabuko
kabuko

Reputation: 36302

Your while(wait){} loop is blocking the UI thread. onPostExecute runs on the UI thread. Since you're blocking, onPostExecute can never execute. Additionally you're creating a new instance of the Load AsyncTask and executing it in onPostExecute, meaning you'll have an infinite loop of these unless you cancel at some point.

Upvotes: 2

0xC0DED00D
0xC0DED00D

Reputation: 20348

Looks like your doInBackground() method is throwing an Exception, try putting it in a try-catch block.
Also I don't know why you are calling super.onPostExecute(), try removing this too, it's not necessary to use this statement.

Upvotes: 2

Ted Hopp
Ted Hopp

Reputation: 234795

This code:

public void click() {
new Load().execute();
while(wait) {
;
}
}

will block the UI thread while the task executes. This is as bad as just running the background task in the foreground and should cause an Application Not Responding (ANR) error. Please don't do it.

Note that AsyncTask.onPostExecute() will not be called if the task is cancelled. It also won't be called if doInBackground throws an exception. Whatever is going on in doInBackground may be causing this.

Upvotes: 5

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