این هم توابعی که من ایجاد کزدم
این در صورتیه که در فایل APP.CONFIG پسورد رو تغییر داده باشیم تا کسی متوجه پسورد اصلی نشه....



 Friend Function EntityConnectionString(Database As String, Password As String,

                                     ParamArray MetadataResources() As String) As String

            Dim connString As String = "Data Source=|DataDirectory|" + Database + ";Password=" + Password + ";Persist Security Info=True"

            Dim esb As EntityConnectionStringBuilder = New EntityConnectionStringBuilder()

            For I = 0 To MetadataResources.Length - 1

                MetadataResources(I) = MetadataResources(I).Insert(0, "res://*/") 

            Next

            Dim expr As String = Join(MetadataResources, "|")

            esb.Metadata = expr

            esb.Provider = "System.Data.SqlServerCe.3.5"

            esb.ProviderConnectionString = connString

            Return esb.ToString()

        End Function

        Friend Sub ChangeDataBase()

            'name=KeyStoreEntities

            Dim CS = EntityConnectionString("\Database\KeyStore.sdf",

                                                      "123456",

                                                      "Database.KeyStore.csdl",

                                                      "Database.KeyStore.ssdl",

                                                      "Database.KeyStore.msl")

            KeyStoreData = New KeyStoreEntities(CS)

        End Sub