Delphi change scale and layout

Question

I'm trying to make my program change the layout scale at runtime. I developed this code based on an existing powershell script. But it compiles but when running, it returns an error.

Error:

The procedure entry point SystemParametersInfo could not be located in the dynamic link library.

var
  Form1: TForm1;

  function SystemParametersInfo(uiAction, uiParam: UINT; pvParam: Pointer; fWinIni: UINT): BOOL; stdcall; external 'user32.dll';

implementation

{$R *.dfm}

function SetScaling: Boolean;
begin
 Result := SystemParametersInfo($000F, 125, nil, 1);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
 SetScaling;
end;

Why not calling `Windows.SystemParametersInfo()` right away, which every Delphi version already imports? — AmigoJack, Jan 23 '23 at 08:26

score 1 · Answer 1 · answered Jan 23 '23 at 04:04

1

As it is said in the mentioned error there is no function named SystemParametersInfo in user32.dll.

There are two similarly named functions SystemParametersInfoA which is to be used by applications that work with ANSI strings and SystemParametersInfoW which is to be used by applications supporting wide strings like modern Delphi.

NOTE: SystemParametersInfo can only be found on Windows CE 5.0 and it resides in Coredll.lib library.

answered Jan 23 '23 at 04:04

SilverWarior

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which direction should i take? – David Kennedy Jan 23 '23 at 04:15
If using Delphi 2007 or newer then `SystemParametersInfoW ` would most likely be the correct be the correct choice unless you are purposely limiting your application into making use of ANSI Strings.. – SilverWarior Jan 23 '23 at 04:37
@SilverWarior Delphi Unicode versions started with Delphi 2009! – Delphi Coder Jan 23 '23 at 07:00

score 1 · Answer 2 · answered Jan 23 '23 at 04:57

The WinAPI.Windows unit defines the SystemParametersInfo function. No reason to define it locally.

Your call to SystemParametersInfo with a first parameter of $000F is a request to set the screen saver timeout to 125 seconds ($000F=SPI_SETSCREENSAVETIMEOUT).

Setting DPI Scaling is a bit more complex than what you are attempting in the code that you posted. You can read the "how-to" details here.

Delphi change scale and layout

2 Answers2