CHANGEMENT AUTOMATIQUE DE L'IMAGE DE L'ARRIÈRE PLAN LORS DU DÉMARAGE DU WINDOWS

program WallPaper;

uses
  SysUtils, FileCtrl, Windows, Registry;

{$R *.RES}
var
  Directory, FirstFile: String;
  PictureIndex: Integer;
  i: Integer;
  Info: TSearchRec;
  FileFound: Boolean;
  Reg: TRegistry;

begin
  if ParamCount=2 then
  begin
    // Windows executes the program when it starts sending tow parameters

    Directory:=ParamStr(1);
    PictureIndex:=StrToInt(ParamStr(2));
    if DirectoryExists(Directory) then
    begin
      i:=0;
      FileFound:=False;
      if FindFirst(Directory + '*.bmp', faArchive, Info)=0 then
      begin
        FirstFile:=info.Name;

        // Search of picture file in directory
        repeat
          Inc(i);
          if PictureIndex = i then
          begin
            FileFound:=True;
            SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, PChar(Directory+Info.Name), SPIF_UPDATEINIFILE);
            if FindNext(Info) = 0 then Inc(PictureIndex) else PictureIndex:=1;
          end;
        until (FindNext(Info) <> 0) or FileFound;

        // Set first picture file existing in directory
        // as Wallpaper if index picture doesn't exist
        if not FileFound then
        begin
          SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, PChar(Directory+FirstFile), SPIF_UPDATEINIFILE);
          PictureIndex:=2;
        end;

        // Set next picture's index in the Registry Windows
        Reg:=TRegistry.Create;
        try
          Reg.RootKey := HKEY_LOCAL_MACHINE;
          if Reg.OpenKey('\Software\Microsoft\Windows\CurrentVersion\Run', True) then
            Reg.WriteString('WallPaper', ParamStr(0)+' '+Directory+' '+IntToStr(PictureIndex));
        finally
          Reg.CloseKey;
          Reg.Free;
        end;
      end;
    end;
  end else
  begin
    // User executes the program

    // Select directory of user's pictures
    if SelectDirectory('Select Pictures Directory', '', Directory) then
    begin
      if Length(Directory)<>3 then Directory:=Directory+'\';
      Reg:=TRegistry.Create;
      try
        Reg.RootKey := HKEY_LOCAL_MACHINE;
        if Reg.OpenKey('\Software\Microsoft\Windows\CurrentVersion\Run', True) then
          Reg.WriteString('WallPaper', ParamStr(0)+' '+Directory+' 1');
      finally
        Reg.CloseKey;
        Reg.Free;
      end;
    end;
  end;
end.