Where to detect changing of system metrics

[Semen Matusovski]

Hi, all --
My app doesn't like changing SM_CXSCREEN SM_CYSCREEN and similar.
That's why I want to detect changing and to restart an app.

I expected WM_SETTINGCHANGE message, but under Win2000 I can detect it for changing colors only.
To take and to compare with previous in WM_ACTIVATEAPP is possible, but probably exist better solution ?

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[Matthew Berg]

Does the WM_WININICHANGE message work?

P.S. I just noticed this in the Win32 API help file:

Windows NT: The WM_SETTINGCHANGE message is implemented on the Windows 95 platform. It is not implemented on the Windows NT platform. The Windows NT message WM_WININICHANGE provides equivalent functionality.

Since Windows 2000 is really Windows NT, the WM_WININICHANGE message should work.

[This message has been edited by Matthew Berg (edited October 10, 2000).]

[Semen Matusovski]

Matthew --
thanks, but the same story. And this looks very strange.
Probably, it's a feature of russian release, but I am very doubt.
Anyway, if somebody is able to check, below is simple test code.

   #Compile Exe
   #Dim All
   #Register None
   #Include "WIN32API.INC"

   Function WndProc (ByVal hWnd As Long, ByVal wMsg As Long, _
                     ByVal wParam As Long, ByVal lParam As Long) Export As Long
      Select Case wMsg
         Case %WM_SETTINGCHANGE: SetWindowText hWnd, "%WM_SETTINGCHANGE"
         Case %WM_WININICHANGE : SetWindowText hWnd, "%WM_WININICHANG"
         Case %WM_DESTROY      : PostQuitMessage 0: Function = 0: Exit Function
      End Select
      Function = DefWindowProc(hWnd, wMsg, wParam, lParam)
   End Function

   Function WinMain (ByVal hInstance As Long, ByVal hPrevInstance As Long, _
      lpCmdLine As Asciiz Ptr, ByVal iCmdShow As Long) As Long

      Local Msg         As tagMsg
      Local wndclass    As WndClassEx
      Local szAppName   As Asciiz * 80
      Local hWnd        As Long

      szAppName              = "Test"
      wndclass.cbSize        = SizeOf(WndClass)
      wndclass.style         = %CS_HREDRAW Or %CS_VREDRAW
      wndclass.lpfnWndProc   = CodePtr(WndProc)
      wndclass.hInstance     = hInstance
      wndclass.hCursor       = LoadCursor( %NULL, ByVal %IDC_ARROW )
      wndclass.hbrBackground = GetStockObject( %WHITE_BRUSH )
      wndclass.lpszClassName = VarPtr( szAppName )
      wndclass.hIconSm       = LoadIcon( hInstance, ByVal %IDI_APPLICATION )

      RegisterClassEx wndclass

      hWnd = CreateWindow(szAppName, "Place for a message", %WS_SYSMENU Or %WS_THICKFRAME, _
          %CW_USEDEFAULT, %CW_USEDEFAULT, %CW_USEDEFAULT, %CW_USEDEFAULT, _
           %NULL, %NULL, hInstance, ByVal %NULL)
      ShowWindow hWnd, iCmdShow
      UpdateWindow hWnd

      While GetMessage(Msg, %NULL, 0, 0)
         TranslateMessage Msg
         DispatchMessage Msg
      Wend
      Function = msg.wParam
   End Function  ' WinMain

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E-MAIL: [email protected]

[Per Fimmeland]

Semen,
I ran Your test-code, but nothing happened...
Added Case %WM_DISPLAYCHANGE to WndProc and then it worked.
(only tested on Win2k)

   Function WndProc (ByVal hWnd As Long, ByVal wMsg As Long, _
                     ByVal wParam As Long, ByVal lParam As Long) Export As Long
      Select Case wMsg
         Case %WM_SETTINGCHANGE: SetWindowText hWnd, "%WM_SETTINGCHANGE"
         Case %WM_WININICHANGE : SetWindowText hWnd, "%WM_WININICHANG"
         Case %WM_DISPLAYCHANGE: SetWindowText hWnd, "%WM_DISPLAYCHANGE"
         Case %WM_DESTROY      : PostQuitMessage 0: Function = 0: Exit Function
      End Select
      Function = DefWindowProc(hWnd, wMsg, wParam, lParam)
   End Function

Microsoft writes:

The WM_DISPLAYCHANGE message is sent to all windows when the display resolution has changed

WM_DISPLAYCHANGE
cBitsPerPixel = wParam;
cxScreen = LOWORD(lParam);
cyScreen = HIWORD(lParam);

Parameters
cBitsPerPixel : Specifies the new image depth of the display in bits per pixel.
cxScreen : Specifies the new horizontal resolution of the screen.
cyScreen : Specifies the new vertical resolution of the screen.

Remarks
This message is only sent to top-level windows. For all other windows it is posted
.

-p


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[This message has been edited by Per Fimmeland (edited October 11, 2000).]

[Semen Matusovski]

Per --
According MSDN WM_DISPLAYCHANGE should work in all OSes.
It looks (at least under Win 2000) that, if to change something in "Design" tab (Control Panel, Display) appears %WM_SETTINGCHANGE.
If "Settings" - %WM_DISPLAYCHANGE.

Hope, that if I'll use CASE %WM_DISPLAYCHANGE, %WM_SETTINGCHANGE instead of %WM_ACTIVATEAPP this will be enough.
Thanks.



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