[VB/API] Find hWnd, ClassName, or Window Caption. And close external apps

[Daskalos]

With this app you can find a window caption by its hwnd or ClassName, can find hwnd by caption or classname, find classname by hwnd or window caption and so on ;-)
also can close an external app by hWnd, Window Caption or ClassName

Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, _
                                                                      ByVal lpWindowName As String) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, _
                                                                        ByVal wMsg As Long, _
                                                                        ByVal wParam As Long, _
                                                                        ByVal lParam As Long) As Long
Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" (ByVal hwnd As Long, _
                                                                          ByVal lpClassName As String, _
                                                                          ByVal nMaxCount As Long) _
                                                                          As Long
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, _
                                                                           ByVal lpString As String, _
                                                                           ByVal cch As Long) As Long
Private Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long
                                                                           
Private Const WM_SYSCOMMAND = &H112
Private Const SC_CLOSE = &HF060&
Public dl&
Public xhwnd&
 
 
Private Function GetText(Get_hWnd As Long) As String
Dim lenTxt As Long, retText As String
 
lenTxt = GetWindowTextLength(Get_hWnd) + 1
 
retText = String$(lenTxt, " ")
GetWindowText Get_hWnd, retText, lenTxt
 
GetText = retText
 
End Function
 
Private Sub Command1_Click()
    Text2.Text = FindWindow(vbNullString, Text1.Text)
End Sub
 
Private Sub Command2_Click()
Dim s As String
    s = Space$(255)
  
    Call GetClassName(Text2.Text, s, Len(s))
    
    If InStr(1, s, vbNullChar) Then
        s = Left$(s, InStr(1, s, vbNullChar) - 1)
    End If
    Text3.Text = s
End Sub
 
Private Sub Command3_Click()
    Text2.Text = FindWindow(Text3.Text, vbNullString)
End Sub
 
Private Sub Command4_Click()
Text1.Text = GetText(Text2.Text)
End Sub
 
Private Sub Command5_Click()
    Text1.Text = GetText(FindWindow(Text3.Text, vbNullString))
End Sub
 
Private Sub Command6_Click()
Select Case True
    Case Option1.Value = True
        xhwnd = FindWindow(vbNullString, Text1.Text)
        dl = SendMessage(xhwnd, WM_SYSCOMMAND, SC_CLOSE, 0&)
    Case Option2.Value = True
        dl = SendMessage(Text2.Text, WM_SYSCOMMAND, SC_CLOSE, 0&)
    Case Option3.Value = True
        xhwnd = FindWindow(Text3.Text, vbNullString)
        dl = SendMessage(xhwnd, WM_SYSCOMMAND, SC_CLOSE, 0&)
    Case Else
        Exit Sub
End Select
End Sub