SqlConnection.Open()解决思路

SqlConnection.Open()
请问在一个Sub里使用SqlConnection和SqlCommand,当跳出Sub时,需不需要把SqlConnection和SqlCommand设为Nothing,并SqlConnection.Close()   ???
因为如果预到异常时,Sub可能会中止,这样的话SqlConnection和SqlCommand会不会还存活着?

Private   Sub   Button2_Click(ByVal   sender   As   System.Object,   ByVal   e   As   System.EventArgs)   Handles   Button2.Click
             
                                Dim   SqlConnection1   As   New   System.Data.SqlClient.SqlConnection
                                Dim   SqlCommand1   As   New   System.Data.SqlClient.SqlCommand

                                SqlConnection1.ConnectionString   =   strModConnectionString
                                SqlCommand1.Connection   =   SqlConnection1
                                SqlConnection1.Open()

                                SqlCommand1.CommandText   =   "Select   count(*)   from   Table "
                                Msgbox   "SqlCommand1.ExecuteScalar() "
                                '需不需要加入这几行代码?
                                SqlCommand1=Nothing
                                SqlConnection1.Close()
                                SqlConnection1=Nothing

End   Sub

------解决方案--------------------
根据我遇到的情况，这里面的对象还存在，你可以使用try 块去控制它，
Dim SqlConnection1 As System.Data.SqlClient.SqlConnection
Dim SqlCommand1 As System.Data.SqlClient.SqlCommand

try
sqlconnection1 = new sqlclient.sqlconnect
SqlConnection1.ConnectionString = strModConnectionString
sqlcommand1= new sqlclient.sqlcommand
SqlCommand1.Connection = SqlConnection1
SqlConnection1.Open()

SqlCommand1.CommandText = "Select count(*) from Table "
Msgbox "SqlCommand1.ExecuteScalar() "
Catch ex As Exception
msgbox ex.massage
finally
SqlCommand1=Nothing
SqlConnection1.Close()
SqlConnection1=Nothing
end try

这样可以在发生错误后，将连接对象释放掉
------解决方案--------------------
只需要SqlConnection1.Close()就行了
如果是2005，用Using conn as new sqlconnection()
........
end using
这样它会自动释放掉