DllCall

[trancexx]

Of course it crashes. You are passing to many parameters to SystemParametersInfo.

I have troubles understanding what actually confuses you. For example I've posted correct and different calls to SystemParametersInfo twice in this thread. Yet you constantly call it wrong. For example, what force drives you to use "*" in return type of the function? Or why are you passing 6 parameters to SystemParametersInfo, when it takes only 4?

Lose unnecessary parameters.

[JohnOne]

I've got no answer proper why I added a *, I dont know.

Whats confusing me is the last param $WM_WININICHANGE, http://msdn.microsoft.com/en-us/library/ms725497%28v=VS.85%29.aspx says that, that itself has 2 arguments.

wParam

When the system sends this message as a result of a SystemParametersInfo call, the wParam parameter is the value of the uiAction parameter passed to the SystemParametersInfo function

lParam

When the system sends this message as a result of a SystemParametersInfo call, lParam is a pointer to a string that indicates the area containing the system parameter that was changed.

I'm just confused about it from the ground up.

[trancexx]

I've got no answer proper why I added a *, I dont know.

Whats confusing me is the last param $WM_WININICHANGE, http://msdn.microsoft.com/en-us/library/ms725497%28v=VS.85%29.aspx says that, that itself has 2 arguments.

wParam

When the system sends this message as a result of a SystemParametersInfo call, the wParam parameter is the value of the uiAction parameter passed to the SystemParametersInfo function

lParam

When the system sends this message as a result of a SystemParametersInfo call, lParam is a pointer to a string that indicates the area containing the system parameter that was changed.

I'm just confused about it from the ground up.

System sends as a result of your call to SystemParametersInfo, not you. You just say to system send on don't send depending on fWinIni parameter of the SystemParametersInfo. Edited August 3, 2010 by trancexx

[trancexx]

Ok thanks trancexx (sorry for testing your patience)

I got it right in the end and the calls go smoothly

Unfortunately I think it simply does not work.

I can disable font smoothing altogether and enable it, but that does not help,

This disables/enables font smoothing.

$SPI_SETFONTSMOOTHING = 0x004B
$aCall = DllCall("user32.dll", "bool", "SystemParametersInfo", _
        "dword", $SPI_SETFONTSMOOTHING, _
        "dword",0 , _ ; 1 for enable or 0 for disable
        "dword",0, _
        "dword",0 )

ConsoleWrite(_WinAPI_GetLastErrorMessage())

And this is supposed to change font smoothing types

$WM_WININICHANGE = 0x001A
$SPI_SETFONTSMOOTHINGTYPE = 0x200B
;$SPI_SETCLEARTYPE = 0x1049
$aCall = DllCall("user32.dll", "bool", "SystemParametersInfo", _
        "dword", $SPI_SETFONTSMOOTHINGTYPE, _
        "dword", 0, _
        "dword*", 1, _ ; 1 for standard or 2 for cleartype (default is supposed to be standard)
        "dword", $WM_WININICHANGE)

ConsoleWrite(_WinAPI_GetLastErrorMessage())

So Im finished with this method now and looking for another.

Don't worry about my patience.

You are still not calling it right. I mean that part that's not working.

Following the documentation precisely is very important with DllCall() and related functions. You still have your own (wrong) interpretation of the parameters.

Let me quote MSDN about the last parameter:

fWinIni [in]

UINT

If a system parameter is being set, specifies whether the user profile is to be updated, and if so, whether the WM_SETTINGCHANGE message is to be broadcast to all top-level windows to notify them of the change.

This parameter can be zero if you don't want to update the user profile or broadcast the WM_SETTINGCHANGE message, or it can be one or more of the following values.

Value   Meaning
SPIF_UPDATEINIFILE
Writes the new system-wide parameter setting to the user profile.
SPIF_SENDCHANGE
Broadcasts the WM_SETTINGCHANGE message after updating the user profile.
SPIF_SENDWININICHANGE
Same as SPIF_SENDCHANGE.

Tell me, where do you see them suggesting you should pass WM_WININICHANGE as last parameter to SystemParametersInfo function?

[JohnOne]

Ok thanks trancexx (sorry for testing your patience)

I got it right in the end and the calls go smoothly

Unfortunately I think it simply does not work.

I can disable font smoothing altogether and enable it, but that does not help,

This disables/enables font smoothing.

$SPI_SETFONTSMOOTHING = 0x004B
$aCall = DllCall("user32.dll", "bool", "SystemParametersInfo", _
        "dword", $SPI_SETFONTSMOOTHING, _
        "dword",0 , _ ; 1 for enable or 0 for disable
        "dword",0, _
        "dword",0 )

ConsoleWrite(_WinAPI_GetLastErrorMessage())

And this is supposed to change font smoothing types

$WM_WININICHANGE = 0x001A
$SPI_SETFONTSMOOTHINGTYPE = 0x200B
;$SPI_SETCLEARTYPE = 0x1049
$aCall = DllCall("user32.dll", "bool", "SystemParametersInfo", _
        "dword", $SPI_SETFONTSMOOTHINGTYPE, _
        "dword", 0, _
        "dword*", 1, _ ; 1 for standard or 2 for cleartype (default is supposed to be standard)
        "dword", $WM_WININICHANGE)

ConsoleWrite(_WinAPI_GetLastErrorMessage())

So Im finished with this method now and looking for another.