README.md

Description

This tutorial teaches syntax migration from VB6 to VB.NET with simple VB7/VB.NET comparison.

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Source Code

	<center><STRONG><U>Tutorial: How do I do it in VB.NET?</U></STRONG></center>
	<CENTER> </CENTER>
	<CENTER>This tutorial explain some of the more common migrating problems from VB to
		VB.NET.
	</CENTER>
	<CENTER> </CENTER>
	<UL>
		<LI>
			<DIV align="left"><STRONG>DoEvents</STRONG>
				<BR>
				<BR>
				VB6<BR>
				<FONT face="Courier New Baltic">DoEvents<BR>
				</FONT>
				<BR>
				VB7 <BR>
				<FONT face="Courier New">System.Windows.Forms.Application.DoEvents</FONT>
				<BR>
			</DIV>
		</LI>
	</UL>

• App Object
  
  Get the full application filepath
  
  VB6 
  App.Path & App.EXEName
  
  VB7 System.Reflection.Assembly.GetExecutingAssembly.Location.ToString
  
  Get the app's instance
  
  VB6 App.hInstance
  
  VB7
  System.Runtime.InteropServices.Marshal.GetHINSTANCE _(System.Reflection.Assembly.GetExecutingAssembly.GetModules() _(0)).ToInt32()
  
  Check for a previous instance
  
  VB6 
  App.PrevInstance
  
  VB7
  Function PrevInstance() As Boolean
  If Ubound(Diagnostics.Process.GetProcessesByName(Diagnostics.Process.GetCurrentProcess).ProcessName)) > 0 Then
       Return True 
  Else 
       Return False 
  End If
  
  End Sub
  

• Graphics
  
  Load a picture
  
  VB6 
  Picture1.Picture = LoadPicture(path)
  
  VB7 
  Dim img As Image = Image.FromFile(path)
  Picture1.Image = img
  
  Load a icon
  
  VB6
  Me.Icon = LoadPicture(path)
  
  VB7
  Dim ico As New Icon(path)
  Me.Icon = ico
  
  
• File I/0
  
  Read from a file
  
  VB6
  Open path For Input As #1
  Line Input #1, buffer
  Close #1
  
  VB7
  Dim fs As FileStream = File.Open(path, FileMode.OpenOrCreate, _ FileAccess.Read)
  Dim sr As New StreamReader(fs)
  Buffer = sr.ReadLine
  sr.Close
  
  Write to a file
  
  VB6
  Open path For Output As #1
  Write #1, buffer
  Close #1
  
  VB7
  Dim fs As FileStream = File.Open(path, FileMode.OpenOrCreate, _
  FileAccess.Write)
  Dim sr As New StreamWriter(fs)
  sr.Write(buffer)
  sr.Close
  
  
• Errors
  
  Check for an error
  
  VB6
  On Error Goto errhandler
  ...
  errhandler:
  MsgBox(err.Description)
  
  VB7
  Try
       ...
       Throw New Exception("error description goes here")
       ...
  Catch e as Exception
       MsgBox(e.Description)
  End Try
  
  
• Events
  
  Handling an event
  
  In VB7, there is a new keyword called AddHandler. AddHandler makes handling events a snap.
  
  AddHandler object.event, AddressOf procedure