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androidandroid-asynctaskprogressdialog
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Reputation: 10442

ProgressDialog using AsyncTask producing constructor undefined error

public class async extends AsyncTask<String, Integer, String>{
ProgressDialog prog;
@Override
protected void onPreExecute() {

    super.onPreExecute();
    prog=new ProgressDialog(async.this);//This is chowing error 
    prog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    prog.setMax(100);
    prog.show();

}

    @Override
    protected String doInBackground(String... params) {
        for (int i = 0; i < 10; i++) {
        publishProgress(5);
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return null;
    }

@Override
protected void onPostExecute(String result) {

    super.onPostExecute(result);
    prog.dismiss();
}
@Override
protected void onProgressUpdate(Integer... values) {
    prog.setProgress(values[0]);
    super.onProgressUpdate(values);
}
}

The above code is producing the error:

the constructor ProgressDialog(AndroidasynctaskActivity.async) is undefined

Why is this so? Can anyone please help me troubleshoot this?

Upvotes: 0

Views: 3392

Answers (2)

Marvin Pinto
Marvin Pinto

Reputation: 31008

As already mentioned, the reason this is happening is because the ProgressDialog constructor you're using needs a Context object. Here's one example of how you can do this.

Modify your async class and add a single-argument constructor that accepts a Context object. Then modify the onPreExecute method to use said Context. For example:

public class async extends AsyncTask<String, Integer, String>{

  private Context context;
  ProgressDialog prog;

  public async(Context context) {
    this.context = context;
  }


  @Override
  protected void onPreExecute() {
    super.onPreExecute();
    prog=new ProgressDialog(context); 
    prog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
    prog.setMax(100);
    prog.show();
  }

  // ...
}

Then to instantiate and run this AsyncTask:

async mTask = new async(context);
mTask.execute(params);

Upvotes: 6

Noah
Noah

Reputation: 1966

Async tasks do not provide an application or activity context. You may have to pass the context in if this class is contained within the activity that called it.

Upvotes: 2

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