Managing memory consumption from resources can be a hastle to worry about. When using the strongly typed datasets as your DAL (Data Access Layer) to communicate to your database their are two approaches one can take... the easy and reliable way, or the more characters of code and less-forgetful way.
The More-Code Approach involves instantiating the table adapter, create your datatable, fill your datatable with a table adapter's query, iterate over records, and remember to dispose both objects. We will use a User table for these examples.
Code:
Dim UserAdapter As New DALAdapters.UserTableAdapter()
Dim UserDataTable As DALAdapters.UserDataTable = UserAdapter.GetUsers
For Each UserRow As DALAdapters.UserRow In UserDataTable
MsgBox(UserRow.UserName)
Next
UserDataTable.Dispose()
UserAdapter.Dispose()
I used to think this was a clean solution until I realized VB has using as well
This code can be encompassed with a Using block and initialize and dispose any resources as soon as it is finished with them... Not only does it make it more sure-fire because you are guaranteed to free up the used resources, but it it wont even compile if you don't correctly do so, which is done like this.
Code:
Using UserAdapter As New DALAdapters.UserTableAdapter()
Using UserDataTable As DALAdapters.UserDataTable = UserAdapter.GetUsers
For Each UserRow As DALAdapters.UserRow In UserDataTable
MsgBox(UserRow.UserName)
Next
End Using
End Using Another nice advantage of this approach is that it indents the code for you so you KNOW that them variables are only encompassed within that block and could be used again if need be. This is not only for Strongly Typed Datasets... you can use "Using" for anything that you wish to instantly and automatically dispose!
06-28-2007, 09:23 PM
VB.NET 2005 Daily Lesson [6.28.07] - The Power of Using 
Linear Mode
