sending message before close Inno Setup to Windows about rechecking PATH environment variable

Question

ChangesEnvironment in Inno Setup Installer issue.

ChangesEnvironment=yes is the known parameter but it doesn't refresh before installer close.

I am modifying PATH environment variable using Inno-Setup. So as installation completes, default exe starts but throws "dll not found" error. Because of Inno-Setup still not closed and not sending Windows to refresh path environments. I want to make Windows-OS rechecks/updates path environments before setup closed.

So as a temporal solution; I disabled auto-run the default exe and app needs manual open from Desktop icon.

Is there a way to send a message API to windows using Inno-Setup, immediately before Inno-Setup closed ? (Hey Windows! recheck path environments now before get closed)

Answer 1

With the help of Martin, after modifications below, worked perfectly:

[Run]
Filename: "{app}\{#MyAppExeName}"; BeforeInstall: AppendToPathAndRefresh;Description: "{cm:LaunchProgram,{#StringChange(MyAppName, '&', '&&')}}";Flags: nowait postinstall shellexec skipifsilent

[Code]
////////////////////////////////////////////////////////////
const
SMTO_ABORTIFHUNG = 2;
WM_WININICHANGE = $001A;

type
WPARAM = UINT_PTR;
LPARAM = INT_PTR;
LRESULT = INT_PTR;

function SendTextMessageTimeout(hWnd: HWND; Msg: UINT;
wParam: WPARAM; lParam: PAnsiChar; fuFlags: UINT;
uTimeout: UINT; out lpdwResult: DWORD): LRESULT;
external 'SendMessageTimeoutA@user32.dll stdcall';  

procedure RefreshEnvironment;
var
S: AnsiString;
MsgResult: DWORD;
begin
S := 'Environment';
SendTextMessageTimeout(HWND_BROADCAST, WM_WININICHANGE, 0,
    PAnsiChar(S), SMTO_ABORTIFHUNG, 5000, MsgResult);
end;
////////////////////////////////////////////////////////////
function GetProgramFiles(Param: string): string;
begin
if IsWin64 then Result := ExpandConstant('{pf64}')
    else Result := ExpandConstant('{pf32}')
end;

///PATH ENVINRONMENT//////////////////////////////////////////
function Replace(Dest, SubStr, Str: string): string;
var
Position: Integer;
Ok: Integer;
begin
Ok := 1;
while Ok > 0 do
begin
    Position:=Pos(SubStr, Dest);
    if Position > 0 then
    begin
    Delete(Dest, Position, Length(SubStr));
    Insert(Str, Dest, Position);
    end else
    Ok := 0;
end;
Result:=Dest;
end;

procedure AppendToPath();
var
V: string;
Str: string;
begin
RegQueryStringValue(HKLM, 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment', 'Path', V)
Str := ExpandConstant('{app}\libav');
V := Replace(V, Str, '');
V := V + ';' + Str;
V := Replace(V,';;',';');
RegWriteStringValue(HKLM, 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment', 'Path', V)

// MsgBox(V, mbInformation, MB_OK); 
end;

procedure RemoveFromPath();
var
V: string;
Str: string;
begin
RegQueryStringValue(HKLM, 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment', 'Path', V)
Str := ExpandConstant('{app}\dlls');
V := Replace(V, Str, '');
V := Replace(V,';;',';');
RegWriteStringValue(HKLM, 'SYSTEM\CurrentControlSet\Control\Session Manager\Environment', 'Path', V)
//MsgBox(V, mbInformation, MB_OK);
end;

procedure AppendToPathAndRefresh;
begin
AppendToPath;
RefreshEnvironment;
end;

(*
procedure DeinitializeSetup();
begin
AppendToPath();
end;
*)

procedure DeinitializeUninstall();
begin
RemoveFromPath();
end;
///END OF PATH ENVIRONMENT ///////////////////////////////////