VB6 - VB.net Syntax Coversions

VB6 - VB.NET Syntax Conversions
(Part 1)

If you're one of those guys/girls who have that old VB6 code just lying around and would like to migrate over to vb.net without rewriting everything from scratch... then this article should (could) help...

Well written code converts easy

First thing in any conversion (even in converting borland C to VC++ or similiar) is to clean up and make your code as functional and "simple" as possble"

Before converting , you should use a "clean up" concept and be sure to

• Notate the important functionality s of your code using 'Your notes(this will allow you to find code that may have experienced a significant change)
• Declare every single variable.
• make sure all variables have the explicit type (as opposed to variants.)
• Check timers, be sure to set timer1.enabled = false (as opposed to the alternative in vb6 which allowed you to set it to 0 )
• Convert DAO and RDO to ADO.

Consider the following a reference guide, somewhere you can come when you need to migrate your VB6 project to VB.NET

Errors

(check out my errors article)
Handle Your Errors

In VB6
On Error Goto errhandler

__________(code..yada...yada...)

errhandler:
MsgBox(err.Description)

In VB.NET

Try

Throw New Exception("error description")

Catch e as Exception
MsgBox(e.Description)
End Try

Events

Handling an event

In VB.NET,you can us the new keyword AddHandler.

AddHandler object.event, AddressOf procedure

DoEvents

VB6
DoEvents

VB.NET
System.Windows.Forms.Application.DoEvents

App Object

Full Filepath

VB6
App.Path & App.EXEName

VB.NET

System.Reflection.Assembly.GetExecutingAssembly.Lo cation.ToString

App instance

VB6

App.hInstance

VB.NET
System.Runtime.InteropServices.Marshal.GetHINSTANC E _(System.Reflection.Assembly.GetExecutingAssembly. GetModules() _(0)).ToInt32()

Previous Application Instance

VB6
App.PrevInstance

VB.NET
Function PrevInstance() As Boolean
If Ubound(Diagnostics.Process.GetProcessesByName(Diag nostics.Process.GetCurrentProcess).ProcessName)) > 0 Then
Return True
Else
Return False
End If

End Sub

Graphics

Load Picture

VB6
Picture1.Picture = LoadPicture(path)

VB.NET
Dim imgf As Image = Image.FromFile(path)
Picture1.Image = imgf

Load icons

VB6
Me.Icon = LoadPicture(path)

VB.NET
Dim icof As New Icon(path)
Me.Icon = icof

File I/0

Read File

VB6
Open path For Input As #1
Line Input #1, buffer
Close #1

VB.NET
Dim fst As FileStream = File.Open(path, FileMode.OpenOrCreate, _ FileAccess.Read)
Dim srf As New StreamReader(fst)
Buffer = srf.ReadLine
srf.Close

Write in a file

VB6
Open path For Output As #1
Write #1, buffer
Close #1

VB.NET
Dim fst As FileStream = File.Open(path, FileMode.OpenOrCreate, _
FileAccess.Write)
Dim srw As New StreamWriter(fst)
srw.Write(buffer)
srw.Close

Note: This again is a reference guide, so if your new to vb.net and used vb6 in the past and are looking to make the transistion, start here.


Hope this helps

Gj

this is nice. Thanks a lot