System Delphi

Title: How to use forms declared in DLL by an executable
program Dlloader;
uses
Sharemem,
Forms,
exeunit1 in 'exeunit1.pas' {Form1},
DllIntfu in 'DllIntfu.pas';
{$R *.RES}
begin
Application.Initialize;
Application.CreateForm(TForm1, Form1);
Application.Run;
end.
//--------------------------
unit DllIntfu;
interface
type
TDllobject = class
protected
function Get_UserName: string; virtual; abstract;
procedure Set_UserName(Value: string); virtual; abstract;
public
property UserName: string read Get_UserName write Set_UserName;
end;
TDllobjectClass = class of TDllobject;
implementation
end.
//---------------------------
unit exeunit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics,
Controls, Forms, Dialogs, DllIntfu, StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.DFM}
type
TDllfunc = function: TDllobjectClass;
stdcall;
procedure TForm1.Button1Click(Sender: TObject);
var
i: DWORD;
fHandle: THandle;
fDllfunc: TDllfunc;
fDllobject: TDllobject;
fUserName: string;
begin
fHandle := LoadLibrary('UserName.dll');
if (fHandle 0) then
begin @fDllfunc := GetProcAddress(fHandle, 'Dllfunc');
if Assigned(@fDllfunc) then
begin
i := 255;
SetLength(fUserName, i);
GetUserName(PChar(fUserName), i);
fUserName := StrPas(PChar(fUserName));
fDllobject := fDllfunc.Create;
fDllobject.UserName := fUserName;
ShowMessage(fDllobject.UserName);
fDllobject.Free;
end;
FreeLibrary(fHandle);
end;
end;
end.
//-------------------------------
library UserName;
uses
Sharemem,
Sysutils,
DllIntfu;
type
TCustomDllobject = class(TDllobject)
private
fUserName: string;
function Getfilecount: Integer;
protected
function Get_UserName: string; override;
procedure Set_UserName(Value: string); override;
end;
TCustomDllobjectclass = class of TCustomDllobject;
function TCustomDllobject.Getfilecount: Integer;
var
doserr: Integer;
fsrch: TSearchRec;
begin
Result := 0;
doserr := FindFirst('*.*', faanyfile, fsrch);
if (doserr = 0) then
begin
while (doserr = 0) do
begin
if (fsrch.attr and faDirectory) = 0 then
Inc(Result);
doserr := findnext(fsrch);
end;
FindClose(fsrch);
end;
end;
function TCustomDllobject.Get_UserName: string;
begin
Result := 'You signed on as ''' + fUserName + '''' +
' and there ' + IntToStr(Getfilecount) +
' files in this directory.';
end;
procedure TCustomDllobject.Set_UserName(Value: string);
begin
fUserName := Value;
end;
function Dllfunc: TCustomDllobjectClass; stdcall;
begin
Result := TCustomDllobject; // class type only
end;
exports
Dllfunc name 'Dllfunc';
begin
end.