c# - Medication reminder app -

i creating medication reminder app , here how works; creates directory store new medications' details user enters them, these stored text file name of medication file identifier. user able view list of stored medications , details of method searches directory. however, upon deleting 1 medication file directory, name remains in listbox shows existing names, can still create new file same name , names displayed together. think failing clear contents of listbox shows list of existing files have tried best still cannot working. code use deleteing file follows:

    try     {        // string filename = medlistbox.selecteditem.tostring() + ".txt";         isolatedstoragefile storageaccessor = isolatedstoragefile.getuserstoreforapplication();         /*while (storageaccessor.fileexists(filename))             storageaccessor.deletefile(filename);*/         storageaccessor.createdirectory("medicationdetails");         // string fileholderreappear = medlistbox.selecteditem.tostring() + ".txt";         storageaccessor.deletefile(medlistbox.selecteditem.tostring() + ".txt");         messagebox.show("deleted successfully!");           using (var isofilestream = new isolatedstoragefilestream("meddetailsfile.txt", filemode.open, storageaccessor))         {             string buff;             using (var isofilereader = new streamreader(isofilestream))             {                 while ((buff = isofilereader.readline()) != null)                 {                        medlistbox.items.remove(buff);                  }              }         }         navigationservice.navigate(new uri("/medicationlist.xaml", urikind.relative));      }     catch (exception exception3)     {         messagebox.show("error!!", exception3.message, messageboxbutton.ok);     } }