Question

On a menu item click, I want to pop a dialog box.

private void getAcLookUpDialog() 
 {
try
     {
         Dialog dlg = new Dialog(this); 
         dlg.setContentView(R.layout.aclookup);
         dlg.setTitle(Html.fromHtml("<b><H2>" + "Select A/C # " + "</H2></b>" ));   
         startManagingCursor(cur); 
         cur = actable.getAllAC();
         Log.d("Testing", "No of AC are " + cur.getCount());
         ListView lv = (ListView) findViewById(R.id.aclookuplist);

         SimpleCursorAdapter adapter1 = new SimpleCursorAdapter (this, R.layout.aclookup_listitem, cur, new String[] {"AC"}, new int[] {R.id.acactext});
         lv.setAdapter(adapter1);
         dlg.show();
     }
     catch(Exception e)
     {
         Log.d("Testing", "In getACLookUpdialog: error is: "+ e.toString());
     }

 }

It’s throwing

12-13 08:58:43.968: DEBUG/Testing(3563): In getACLookUpdialog: error is: java.lang.NullPointerException

The query is getting data. I tried to put diff query which is working in my other app.
aclookup.xml has a single listview.
aclookup_listitem has a single textview.

What am I doing wrong ?

Answer 1

First; when you have logged your errormessage with Log, call e.printStackTrace() to get all the details of the exceptions (e.g. on what line it occurred).

You get your error on

lv.setAdapter(adapter1);

as lv is null.

I assume that the ListView exists in the dialog layout (R.layout.aclookup), so it is in the dialog you’ll want to search for the ListView:

ListView lv = (ListView) dlg.findViewById(R.id.aclookuplist);