http://stackoverflow.com/questions/2584598/linq-sqlmethods-like-fails
this article help me,.
LIKE 'a%' => StartsWith("a")
LIKE '%a' => EndsWith("a")
LIKE '%a%' => Contains("a")
LIKE 'a%b' => StartsWith("a") && EndsWith("b")
LIKE '%a%b%' => StartsWith("a") && Contains("b")
now my code is
dataGrid1.DataContext = from re in MainWindow.mcsEntity.mcs_hall re.mcs_Hall_Name.Contains(txt_Search.Text.Trim())
thank u very much,.