can't get findwindow to work - newbie question

[imjbhowe]

I am trying to test for an open window using findwindow but I always get a value returned in the hwnd variable whether the app is open or not. I have tried putting garbage in for the caption name and it still returns numbers. All the info out there on find window indicates that if the window you are testing for is closed, it should return 0 but I can't get it to return 0. Any help is appreciated, here is the code.

Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim hwnd As Long
hwnd = FindWindow("XLMAIN", 0)
If hwnd <> 0 Then
MessageBox.Show(&quot;The window handle is &quot; & hwnd)
Else
MessageBox.Show(&quot;the app is not running&quot
End If

End Sub

 

[Guest_imported]

You should use:

Imports System.Runtime.InteropServices

Public Class MyApi
<DllImport(&quot;user32.dll&quot> Public Shared Function _
FindWindow(ByVal strClassName As String, ByVal _ strWindowName As String) As Integer
End Function
End Class

...
MyApi.FindWindow(...)
...

As opposed to:
Public Declare Function FindWindow Lib &quot;user32&quot; Alias &quot;FindWindowA&quot; (ByVal lpClassName As String, ByVal lpWindowName As String) As Long

This old fasioned way doesn't seem to work anymore.

malvarez@clientsoft.com

 

[imjbhowe]

Thanks, worked great!