[RESOLVED] ShellExecuteA

[schaefer]

Seem to be having a lot of problems switching an old VB6 API to work in .NET. I was using the ShellExecuteA to open documents/images/drawings in their appropriate application. Now in .NET I'm getting an error that the call to PInvoke has unbalanced the stack. Does anyone know what that means or how to correct it?

[RobDog888]

Welcome to the Forums.

You need to declare it correctly for .NET.

Imports System.Runtime.InteropServices

Public Class Form1

	<DllImport("shell32.dll", CharSet:=CharSet.Auto, EntryPoint:="ShellExecute")> _
	Private Shared Function ShellExecute( _
		 ByVal hwnd As IntPtr, _
		 ByVal lpOperation As String, _
		 ByVal lpFile As String, _
		 ByVal lpParameters As String, _
		 ByVal lpDirectory As String, _
		 ByVal nShowCmd As Integer) As Integer
	End Function
End Class

[Hack]

Have you looked at using System.Diagnostics.Process.Start rather than ShellExecute?

[RobDog888]

That is an equilivalent but ShellExecute API may still be needed over process.start in some instances.
Plus he mentioned how to declare APIs in .NET

[Hack]

But, many times that is because he could be unaware there are .NET alternatives to APIs

I sure know I didn't know that when I started, and for a long keep using APIs that I no longer needed.

[RobDog888]

Yes, but there arent .NET equilivalents for most of the APIs.

[Hack]

I've yet to run into a situation where in VB6 I used an API, and when converting to VB.NET, there wasn't a class available that I could use in its stead.

That could happen, but, so far it hasn't.

[schaefer]

Wow, excellent. Thanks very much the System.Diagnostics.process.start works fine and I elminated that complex routine I had been using.

[RobDog888]

Ok great.

Ps, dont forget to Resolve your thread from the Thread Tools menu so others know your question has been answered.

[Hack]

Wow, excellent. Thanks very much the System.Diagnostics.process.start works fine and I elminated that complex routine I had been using.

I'm glad...as I mentioned, for the most part, the APIs that you using in VB6 can be handled by a .NET class, so before just porting the APIs over, I would do some research, or perhaps post a question here in the .NET section, on what would be the VB.NET equivalent to [insert API name here]

[RobDog888]

Well there really isnt too many .NET equilivalents of APIs. There are over over 7,000 new APIs for Vista alone and most of the common ones dont have equilivalents.

For example:
SendMessage, PostMessage, FindWindow, FindWindowEx, GetWindowLong, SetWindowLong etc. all are very commly used in VB 6 apps but have no equilivalents in .NET.

SendKeys is not an equilivalent as it doesnt directly send the contents to a specific window but rather whichever window has the input focus.


Unmanaged API code in .NET is definately something to learn.