vb.net - Error saying file is already open when writing to a file -

i have form fields saving text file.

on same form have button allows view saved prior text file

when hit button reads textfile , displays on datagrid.

this code displaying datagrid

dim reader streamreader     reader = new streamreader("c:\users\john\desktop\tickets.txt")     dim string     dim results() string             = reader.readline         results = a.split(vbtab)         dgv.rows.add(results(0), results(1), results(2), results(3), results(4), results(5))         ' code here         '     loop until nothing      reader.close()     reader.dispose() 

this code saves file

 dim file streamwriter     file = new streamwriter("c:\users\john\desktop\tickets.txt", true)     file.writeline(txtname.text & vbtab & dtdate.text & vbtab & txttime.text & vbtab & txtwho.text & vbtab & txtproblem.text & vbtab & txtresolution.text)     file.close() 

when read records first try save them keep getting error process cannot access file because being used process.

i closed both reader , writer, , not sure why happeneing

better code, sure loop ending?

write:

dim path string = "c:\users\john\desktop\tickets.txt" if file.exists(path)  using sw new streamwriter(path, true)   'code  end using' closes , disposes end if 

read:

dim path string = "c:\users\john\desktop\tickets.txt" if file.exists(path)  dim results new list(of string)  using sr new streamreader(path)   while not sr.endofstream()    results.add(sr.readline())    'better loop   end while  end using' closes , disposes end if  each line in results   'add dgv next