android - How to add Search functionality on list view items in listview are from BaseAdapter -

i have add search functionality on edittext items in listview coming baseadapter using code .getfilter().filter(s.tostring()); not coming

my code :-

approvedfriendlist.setadapter(new approvedlist());              //*********search functionality in approved friend list************************             serch_item.addtextchangedlistener(new textwatcher() {                  @override                 public void ontextchanged(charsequence s, int start, int before, int count) {                     // todo auto-generated method stub                 //  approvedfriendlist.getfiltertoucheswhenobscured().f                 }                  @override                 public void beforetextchanged(charsequence s, int start, int count,                         int after) {                     // todo auto-generated method stub                  }                  @override                 public void aftertextchanged(editable s) {                     // todo auto-generated method stub                  }             });     approvedfriendlist arraylist  

i not getting how use here .getfilter().filter(s.tostring()); approvedlist()(base adapter class ) need urgent please me

first should enable list view filtering adding line of code :

list.settextfilterenabled(true); 

then add text watcher in text view :

text.addtextchangedlistener(new textwatcher() {          @override         public void ontextchanged(charsequence s, int start, int before, int count) {               adapter.getfilter().filter( s.tostring());               list.setadapter(adapter);         }          @override         public void beforetextchanged(charsequence s, int start, int count, int after) {         }          @override         public void aftertextchanged(editable prefix) {          }             });