VB - Getting a Windows Handle Many Ways

[BrandonTurner]

(*Credit Goes to The Hobo*)

How to get a windows HWND
Since many tasks through API can be used on other windows, such as changing a caption or getting a caption, it'd
be important to first now how to obtain the HWND (which is used in most API) of another window. There are two methods
explored below:

Get HWND from caption
This example requires that you know the exact caption of the window, such as 'Untitled' with Notepad.

Option Explicit
 
'declare API:
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
  (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
 
Private Sub Form_Load()
Dim strCaption As String, lhWnd As Long
 
  'Exact caption of the window:
  strCaption = "Untitled - Notepad"
  lhWnd = FindWindow(vbNullString, strCaption)
  
  'if the result is 0, window was not found:
  If lhWnd = 0 Then
    MsgBox "Could not find Notepad..."
  Else
    MsgBox "Notepad found: " & lhWnd
  End If
End Sub

Get HWND from class name
The other method would be to use the window's class name:

Option Explicit
 
'declare API:
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
  (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
 
Private Sub Form_Load()
Dim strClassName As String, lhWnd As Long
 
  'Class Name of the window:
  strClassName = "Notepad"
  lhWnd = FindWindow(strClassName, vbNullString)
  
  'if the result is 0, window was not found:
  If lhWnd = 0 Then
    MsgBox "Could not find Notepad..."
  Else
    MsgBox "Notepad found: " & lhWnd
  End If
End Sub