CODEWITHSUNDEEP
androidprogressdialog
Nimmagadda Gowtham
Nimmagadda Gowtham

Reputation: 270

ProgressDialog - Dialog not showing

I'm new to Progress Dialog. I created a class DBOperations extends AsyncTask and implemented methods onPreExecute and onPostExecute. I made DB calls like 

 newDBOperations().execute( ... );

The onPreExecute and onPostExecute methods invoked perfectly, but i was not able to see the Progress Dialog on my emulator

Code look like 

@Override
protected void onPreExecute() {
    ProgressDialog dialog = new ProgressDialog(context);
    dialog.setCancelable(false);
    dialog.setMessage("Please Wait ...");
    dialog.show();
}

@Override
protected void onPostExecute(Object o) {
    if(dialog != null && dialog.isShowing()) {
        dialog.dismiss();
    }
}

Should i use newHandler().postDelayed ?

Thanks in advance...

Upvotes: 0

Views: 121

Answers (2)

Artur.Sh
Artur.Sh

Reputation: 11

This is how I did it. Works good for me.

Main Activity.java

public class MainActivity extends AppCompatActivity {

Button button;
DBOperations task;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    button = (Button) findViewById(R.id.button); // declared in xml
    button.setOnClickListener(new View.OnClickListener() {  // starts AsyncTask on button click
        @Override
        public void onClick(View v) {
            task = new DBOperations(MainActivity.this); // pass the context to the constructor
            task.execute();
        }
    });
}

}

And DBOperations.java

public class DBOperations extends AsyncTask<Void, Void, Void> {

Context ctx;
ProgressDialog dialog; // should be declared outside onPreExecute

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

@Override
protected void onPreExecute() {
    dialog = new ProgressDialog(ctx);
    dialog.setCancelable(false);
    dialog.setMessage("Please Wait ...");
    dialog.show();
    super.onPreExecute();
}

@Override
protected Void doInBackground(Void... params) {
    try {
        Thread.sleep(3000); // waits 3 seconds
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    return null;
}

@Override
protected void onPostExecute(Void aVoid) {
    if(dialog != null && dialog.isShowing())
        dialog.dismiss();
    super.onPostExecute(aVoid);
}

}

Hope this helps :)

Upvotes: 1

Jeeter
Jeeter

Reputation: 6105

I put this code into an isolated application, and it showed the dialog:

 ProgressDialog dialog = new ProgressDialog(MainActivity.this);
 dialog.setCancelable(false);
 dialog.setMessage("Please Wait ...");
 dialog.show();

It's the exact same code you use, except I replaced your context variable with MainActivity.this

So I believe the context variable you are using is an issue. Make sure you're using the correct Context.

Also, as @MdSufiKhan pointed out in the comments, you won't be able to dismiss it properly, since you create it locally in onPreExecute(). Leave it as a field of DBOperations

Upvotes: 0

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