Structures in Classes

[Jay1b]

When i first started to use VB.NET i wrote a large program using VB6 skills (not knowing about classes), i am just trying to convert this program into 'proper' VB.NET language.

 

This code below allows me to enter data into the fields like this:

Fields_OTT(1).FieldName = "Jay"

Fields_OTT(2).FieldName = "Tom"

Fields_OTT(1).FieldName = "Peter"

 

This keeps the same structure for each of the three.

 

   Public strSettings As String
   Public strSeqNo As Integer
   Public intComPort As Integer
   Public strDestinationDirectory As String
   Public strJournalDirectory As String

   Public Structure StructField
       Public FieldName As String
       Public FieldStartPos As Integer
       Public FieldLength As Integer
   End Structure

   Public Fields_OTT() As StructField
   Public Fields_BIW() As StructField
   Public Fields_SSN() As StructField

 

Trying to put this into a class has proved a nightmare. Could someone please direct me in doing so...

 

Thanks

[DiverDan]

Hi Jay,

 

Here's a simple example of one of my Public Structure Classes

<Serializable()> Public Class stuRaceway

   Public RacewayType As String
   Public TradeSizeSAE As String
   Public TradeSizeMM As String
   Public DecimalSize As Double
   Public Diameter As Double
   Public Area As Double
   Public Unit As String
   Public Index As Integer

End Class

 

I have marked it as Serializable for file saving.

You must create either a referance or a new instance of the Class to use it

 

Dim Raceway as stuRaceway - for using the structure

Dim Raceway as New stuRaceway - for creating new Raceways

 

then:

Raceway.RacewayType = 'blah

etc.

[Jay1b]

Thanks. But using Structures the way i was previously doing it, i could do the following.

 

For i = 1 To 100 Do
  action = Fields_OTT(i).FieldName
  action = Fields_OTT(i).FieldStartPos
  action = Fields_OTT(i).FieldLength
End For

 

The way you suggested couldnt be done like this. (I've already thought about that).

 

Edit: Unless this would work?

Dim blah() As New ClassName

 

Thanks again.

[DiverDan]

That's about what my post said.....and it does work.

 

Dim Raceway as stuRaceway - for using the structure

Dim Raceway as New stuRaceway - for creating new Raceways

 

Are you using an array list for holding or extracting the information?

 

As you may already know, Class structures are only the structure of a collection and not the collection itself.

 

If you are using an ArrayList called Raceways that is either populated from file or from RAM then use:

 

Dim Raceway as stuRaceway

For Each Raceway in Raceways

'blah

Next

This utilizies the Raceway structure to obtain information from the ArrayList

 

For adding new Raceways to the Arraylist use:

For i = 0 to 100

Dim newRaceway As New stuRaceway

 

'assuming that you're filling the ArrayList from an existing array

newRaceway.something = action(i)

newRaceway.somethingelse = action(i + 1)

'etc.

Raceways.Add(newRaceway)

Next

This adds new Raceways in the stuRaceway structure to the ArrayList - or whatever format of collection database you are using.

Edited March 14, 2005 by DiverDan

[Jay1b]

Thanks your a genious. :D