Question

click the button to call this method:

private void goRegister(final boolean isUsername) {
    new Loading.LoadTast(ctx) {

        @Override
        protected String doInBackground(Integer... params) {
            Looper.prepare();
            String msg=doRegister(isUsername);
            closeProgressDialog();
            if(msg == null || msg.length() == 0) {
                SmartNgApplication.getInstance().exit();
            } else {
                BaseHelper.showToast(ctx, msg);
            }
            Looper.loop();
            return null;
        }

    }.execute();
}

and this is LoadTast class:

public abstract static class LoadTast extends AsyncTask <Integer, Integer, String > {

    private ProgressDialog progressDialog;

    private Context ctx;

    public LoadTast(Context ctx) {
        this.ctx=ctx;
    }

    protected abstract String doInBackground(Integer... params);

    public void onPreExecute() {
        super.onPreExecute();
        progressDialog=ProgressDialog.show(ctx, "", "loading...", true, false);
    }

    public void onPostExecute(String result) {
        super.onPostExecute(result);
        progressDialog.dismiss();
        BaseHelper.showToast(ctx, result);
    }

    public void closeProgressDialog() {
        if(progressDialog != null) {
            progressDialog.dismiss();
        }
    }
}

my program is:
when I click 5 times the button don’t call doInbackground method and the screen always run a loading. I guess the code is run onPreExecute and not run doInbackground. Why??
in the AsyncTask has a thread pool,the CORE_POOL_SIZE=5. How to solution the program,Help me thank you !

Answer 1

asyncTask isn’t supposed to run its doInBackground more than once , and it’s also not supposed to be a loopy thread .

asyncTask is supposed to be a one time thing that you run , and you can only assume that if multiple asyncTasks have executed , at least one will run at the same time.

another thing i’ve noticed : you called closeProgressDialog from within doInBackground , but that’s a UI related operation ,while the doInBackground is being ran on a non-UI thread.