widget - Null Pointer implementing Android Wheel -

i'm trying implement yuri kanivets' android wheel picker. trying place few strings onto single wheel. makes implementation little different trying display wheel on alertdialog.builder. can empty wheel appear on dialog, can't seem populate anything. every time try add values wheel, null pointer exception.

if familiar this, can see doing wrong? suspect context using in arraywheeladapter wrong, don't know how else it. here code:

@override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_find_events);      layoutinflater inflater = layoutinflater.from(this);     builderview = inflater.inflate(r.layout.wheel_range_layout, null);     alertdialog.builder builder = new alertdialog.builder(this);     builder.setview(builderview);            alert = builder.create();      final wheelview range = (wheelview) findviewbyid(r.id.range);     int defaultrange = 0;     string ranges[] = new string[] {"10 miles", "25 miles", "50 miles", "everywhere"};      arraywheeladapter<string> adapter = new arraywheeladapter<string>(this, ranges);     adapter.settextsize(18);      //this next line crashing -- maybe adapter null???     range.setviewadapter(adapter);     range.setcurrentitem(defaultrange);      alert.show(); } 

use

final wheelview range = (wheelview)builderview. findviewbyid(r.id.range); 

instead of

final wheelview range = (wheelview) findviewbyid(r.id.range); 

for initializing wheelview range instance because wheelview view in dialogbox wheel_range_layout layout instead of activity layout