Zjištění ztráty a získání focusu
Postup:
Založte nový projekt, přidejte modul a v něm deklarujte:
Private
Declare Function CallWindowProc Lib "user32" Alias _
"CallWindowProcA" (ByVal lpPrevWndFunc As Long, _
ByVal hwnd As Long, ByVal Msg As Long, _
ByVal wParam As Long, ByVal lParam As Long) As Long
Private Declare Function SetWindowLong Lib "user32" _
Alias "SetWindowLongA" (ByVal hwnd As Long, _
ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Const WM_ACTIVATEAPP = &H1C
Private Const GWL_WNDPROC = -4
Public lpPrevWndProc As Long
Public gHW As Long
Public Sub Hook()
lpPrevWndProc = SetWindowLong(gHW, GWL_WNDPROC, _
AddressOf WindowProc)
End Sub
Public Sub Unhook()
Dim temp As Long
temp = SetWindowLong(gHW, GWL_WNDPROC, lpPrevWndProc)
End Sub
Function WindowProc(ByVal hw As Long, ByVal uMsg As Long, _
ByVal wParam As Long, ByVal lParam As Long) As Long
'Test události
ActivateApp
If uMsg = WM_ACTIVATEAPP
Then
If wParam = 0 Then 'Aplikace
získala focus
Form1.Caption = "Získán focus"
Else
Form1.Caption = "Ztracen focus"
End If
End If
WindowProc = CallWindowProc(lpPrevWndProc, hw, uMsg, wParam, lParam)
End Function
Do formuláře zapište:
Option Explicit
Sub Form_Load()
gHW = Me.hwnd
Hook
End Sub
Private Sub Form_Unload(Cancel As Integer)
Unhook
End Sub
Spusťte projekt a otestujte.