Question

In an activity, I have two Text Views. In context menu, I have an options to change text size of one of the text view. I tried something like this..

       public boolean onOptionsItemSelected(MenuItem item){
          switch (item.getItemId()){
                  case R.id.menutextSize:
                    final CharSequence[] items = {"Normal","Large","Larger"};
                    AlertDialog.Builder builder = new      

           AlertDialog.Builder(this);
                    builder.setTitle("Select TextSize");
                    builder.setSingleChoiceItems(items, -1, 
                            new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int item) {
                            Toast.makeText(getApplicationContext(), items[item],
                                    Toast.LENGTH_SHORT).show();
                        }
                    });

                    builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int whichButton) {

                            int textSize = (int)mBodyText.getTextSize();  
                            if (items[whichButton] == "Normal")    
                            {
                                mTextv.setTextSize(12);
                            }
                            if (items[whichButton] == "Large")    
                            {
                                mTextv.setTextSize(14);
                            }
                            if (items[whichButton] == "Larger")    
                            {
                                mTextv.setTextSize(16);
                            }




                        }
                    });
                    builder.setNegativeButton("cancel", null);
                    builder.show();
                    return true;    
          }

t when I am clciking in the radiobutton it is showing “Force close ” messsage. How can I solve this?
Thank you..

Answer 1

Your app crashes because it tries to access an element with a negative index in the items array. It happens because of these lines:

if (items[whichButton] == "...")

If you look carefully at DialogInterface.OnClickListener documentation you’ll notice that its onClick() method accepts such constants as BUTTON_POSITIVE, BUTTON_NEUTRAL and BUTTON_NEGATIVE which all are negative and not connected to the list items.