After clicking a button, displaying a modal dialog on the Android is easy, by using the classes android.app.AlertDialog and its helper, android.app.AlertDialog.Builder, with code such as:

               new AlertDialog.Builder(v.getContext())
                .setTitle("My Alert")
                .setMessage("Blah")
                .setPositiveButton(android.R.string.ok, null)
                .show();

Alternatively, if there's a need to hold a reference to the newly created AlertDialog:

        AlertDialog LDialog = new AlertDialog.Builder(v.getContext())
                .setTitle("My Alert")
                .setMessage("Blah")
                .setPositiveButton(android.R.string.ok, null).create();
                LDialog.show();

If no calls are made to setPositiveButton, or setNegativeButton, then no buttons are displayed and pressing the back button is the only way to dismiss the dialog.