vb.net fastest way to remove duplicates from listview? -

does have quicker , better way remove duplicates listview? doing this: sort items alphabetically, , checks item below , compares 1 above.

this time consuming though.. when enter 20.000 records excel sheet, , remove duplicates takes few miliseconds, code below takes hours check 20.000 items in vb.net. know of faster method?

 dim max integer = listview2.items.count     dim integer = 0      each item listviewitem in listview2.items          if = max             exit         end if          if > 0              if item.text = listview2.items(i - 1).text                 max -= 1                 item.remove()                 -= 1             end if         end if          += 1          label4.text = "total domains: " & listview2.items.count      next 

use hashset accept unique values.

dim itemstext = listview2.items.cast(of listviewitem).select(function(item) item.text) dim uniquesvalues hashset(of string) = new hashset(of string)(itemstext)    

then set items hashset listview.