VB/WinAPI, Help:Detecting changes in application focus

Help:Detecting changes in application focus

Author	Message
Timothy J. Bruc #1 / 4	Help:Detecting changes in application focus ick LoseFocus and GotFocus come with all VB Forms at NO EXTRA CHARGE. {filter}ing use the {filter}ing thangs that are {filter}ing obvious on the {filter}ing code pane. -- Respectfully, Timothy J. Bruce Pursuant to US Code, Title 47, Chapter 5, Subchapter II, Sec. 227, any and all nonsolicited commercial E-mail sent to this address is subject to a download and archival fee in the amount of $500 US. E-mailing denotes acceptance of these terms.
Sat, 29 Apr 2000 03:00:00 GMT

Slic #2 / 4	Help:Detecting changes in application focus Quote: >Unfortunately, those events only fire when focus is changed within the >application, not when the application itself loses or gains focus. With >VB5 you should be able to subclass the VB "invisible" window (its a >GetWindow enumeratable parent to your main form) that intercepts all >Windows messages and look for WM_ACTIVATEAPP. A wParam of TRUE means the >app is being activated, and FALSE, means deactivated. Exactly how would trap the WM in VB? Could you post a code snipet, I didn't realize this was possible from VB. Thanx! Quote: >> LoseFocus and GotFocus come with all VB Forms at NO EXTRA CHARGE. >> {filter}ing use the {filter}ing thangs that are {filter}ing obvious on the {filter}ing >code >> pane. My first kill filter ever in a programming news group... Key fingerprint = D3 D2 32 2C 28 B9 0B 05 A4 0B C5 5E 20 FE D7 C6
Sun, 30 Apr 2000 03:00:00 GMT

Schmid #3 / 4	Help:Detecting changes in application focus Hi Slick! Quote: > Exactly how would trap the WM in VB? Could you post a code snipet, I > didn't realize this was possible from VB. VB5: ******Into the Startform of the App***** Private Sub Form_Load() HookHdl = SetWindowsHookExA(4, AddressOf CallWndProc, App.hInstance, App.ThreadID) End Sub Private Sub Form_Unload(Cancel As Integer) UnhookWindowsHookEx HookHdl End Sub *********************************************** ***********Into a Module*********** Type CWPSTRUCT lParam As Long wParam As Long Message As Long Hwnd As Long End Type Public Declare Function SetWindowsHookExA& Lib "user32" (ByVal idHook&, ByVal lpfn&, ByVal hmod&, ByVal ThrID&) Public Declare Function CallNextHookEx& Lib "user32" (ByVal hHook&, ByVal nCode&, ByVal wParam&, lParam As Any) Public Declare Function UnhookWindowsHookEx& Lib "user32" (ByVal hHook&) Public HookHdl& Public Function CallWndProc&(ByVal nCode&, ByVal wParam&, Inf As CWPSTRUCT) On Error Resume Next If nCode < 0 Then CallWndProc = CallNextHookEx(HookHdl, 4, wParam, Inf) Select Case Inf.Hwnd Case Form1.Hwnd Select Case Inf.Message 'Case &H6 'WM_ACTIVATE Case &H1C 'WM_ACTIVATEAPP Debug.Print Inf.wParam '0 = InActive 'Case OtherMessageForThisWindow End Select 'Case OtherWindowHandleInApp End Select End Function ****************************************************** Olaf P.S. Be careful with the Stop-Button in the IDE (GPF because no UnHook)
Sun, 30 Apr 2000 03:00:00 GMT

Slic #4 / 4	Help:Detecting changes in application focus Okay, a hook makes sense. I thougt you were saying that there was a hidden window that VB allowed you to trap the WMs directly.. Quote: >Hi Slick! >> Exactly how would trap the WM in VB? Could you post a code snipet, I >> didn't realize this was possible from VB. >VB5: >******Into the Startform of the App***** >Private Sub Form_Load() > HookHdl = SetWindowsHookExA(4, AddressOf CallWndProc, App.hInstance, >App.ThreadID) >End Sub >Private Sub Form_Unload(Cancel As Integer) > UnhookWindowsHookEx HookHdl >End Sub >*********************************************** >***********Into a Module*********** >Type CWPSTRUCT > lParam As Long > wParam As Long > Message As Long > Hwnd As Long >End Type >Public Declare Function SetWindowsHookExA& Lib "user32" (ByVal idHook&, >ByVal lpfn&, ByVal hmod&, ByVal ThrID&) >Public Declare Function CallNextHookEx& Lib "user32" (ByVal hHook&, ByVal >nCode&, ByVal wParam&, lParam As Any) >Public Declare Function UnhookWindowsHookEx& Lib "user32" (ByVal hHook&) >Public HookHdl& >Public Function CallWndProc&(ByVal nCode&, ByVal wParam&, Inf As CWPSTRUCT) > On Error Resume Next > If nCode < 0 Then CallWndProc = CallNextHookEx(HookHdl, 4, wParam, Inf) > Select Case Inf.Hwnd > Case Form1.Hwnd > Select Case Inf.Message > 'Case &H6 'WM_ACTIVATE > Case &H1C 'WM_ACTIVATEAPP > Debug.Print Inf.wParam '0 = InActive > 'Case OtherMessageForThisWindow > End Select > 'Case OtherWindowHandleInApp > End Select >End Function >****************************************************** >Olaf >P.S. Be careful with the Stop-Button in the IDE (GPF because no UnHook) Key fingerprint = D3 D2 32 2C 28 B9 0B 05 A4 0B C5 5E 20 FE D7 C6
Sun, 30 Apr 2000 03:00:00 GMT

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