Question

I am trying to show a alert box in my app when numberformat exception occurs but for some reason the app crashes

add.setOnClickListener(new View.OnClickListener() {

        public void onClick(View arg0) {
            // TODO Auto-generated method stub

            try {

                preRes = new Double(field1.getText().toString());
                lastCommand = "+";
                field1.setText("");
                count = 0;

            } catch (NumberFormatException e) {    


                show = new AlertDialog.Builder(mContext)
                .setTitle("Error")
                .setMessage("no inputs").setPositiveButton("OK", null).show();

            }

        }
    });

Answer 1

I believe you have to create the Builder before you can begin setting properties. Try something like this (Assuming show is an AlertDialog):

show = new AlertDialog.Builder(mContext).create();
show.setTitle("Error")
  .setMessage("no inputs")
  .setPositiveButton("OK", null)
  .show();