MDI Child form in DLL

[FaNIX]

Hi,

Hopefully someone can help me: I have a MDI Application, but the Child Forms are located in a DLL. So when I load the DLL, i send through the TApplication and TScreen Handle, so that the Child form can be attached to the MDI Application. This works just fine.

Each DLL only has one export procedure, and thats the LoadDLLForm procedure

Delphi-Quellcode:

procedure LoadDLLForm(ATApp : TApplication; S: TScreen; var AMDITabBar : TAdvOfficeMDITabSet); export;
begin

  Application := ATApp;
  Screen      := S;

  frmChild := TfrmChild.Create(Application);
  frmChild.FormStyle := fsMDIChild;
  frmChild.Caption := 'Patient Data';

  AMDITabBar.AddTab(frmChild);
end;

This function will call the MAIN MDICHild form, and all forms from there will be SDI Based. So Basically, only one MDIChild form per DLL,the rest as modal forms.

So this is what I wish to accomplish:

When the ChildForm is closed(wish is located in the DLL), I want the DLL to be distracted/unloaded, but I have no idea how to do this.

Here is my MDI Application Code:

Delphi-Quellcode:

unit uMain;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, AdvOfficeTabSet, StdCtrls;

type
  TfrmMain = class(TForm)
    MDITabBar: TAdvOfficeMDITabSet;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
    procedure LoadMyLibrary(Alib : String);
  public
    { Public declarations }
  end;

  TLoadDLLForm = procedure(ATApp : TApplication; S: TScreen; var AMDITabBar : TAdvOfficeMDITabSet);

var
  frmMain: TfrmMain;
  LoadDLLForm : TLoadDLLForm;

implementation

uses uChild, uChildP;

{$R *.dfm}
 //****************************************************************************//
procedure TfrmMain.Button1Click(Sender: TObject);
begin
  LoadMyLibrary('MyDLL.dll');
end;
 //****************************************************************************//
procedure TfrmMain.LoadMyLibrary(Alib : String);
var
  Handle: THandle;
begin

    Handle := LoadLibrary(PChar(Alib));

    if Handle = 0 then
    begin
      ShowMessage('Error loading dll "'+Alib+'"');
    end
    else
    begin
      @LoadDLLForm := GetProcAddress(Handle, 'LoadDLLForm');
      if @LoadDLLForm <> nil then
      begin
        LoadDLLForm(Application,Screen,MDITabBar);
      end
      else
      begin
        FreeLibrary(Handle);
        ShowMessage('Could not load library');
      end;
    end;

end;
 //****************************************************************************//
end.

DLL Code

Delphi-Quellcode:

library MyDLL;

uses
  SysUtils,
  Classes,
  Windows,
  Forms,
  AdvOfficeTabSet,
  uChild in 'uChild.pas' {frmChild};

var
  PrevApplication  : TApplication;
  PrevScreen       : TScreen;

{$R *.res}
//****************************************************************************//
procedure DLLMain(EntryCode: integer);
begin
  case EntryCode of
    DLL_PROCESS_ATTACH:
    begin
      // Do Initialization stuff here.  Called when a process loads the DLL
      PrevApplication := Application;
      PrevScreen := Screen;
    end;
    DLL_PROCESS_DETACH:
    begin
      // Do Finalization stuff here.  Called when a process unloads the DLL
       FreeLibrary (GetModuleHandle ( 'MyDLL.dll'));
      Application := PrevApplication;
      Screen := PrevScreen;
    end;
  end;
end;
//****************************************************************************//
procedure LoadDLLForm(ATApp : TApplication; S: TScreen; var AMDITabBar : TAdvOfficeMDITabSet); export;
begin

  Application := ATApp;
  Screen      := S;

  frmChild := TfrmChild.Create(Application);
  frmChild.FormStyle := fsMDIChild;
  frmChild.Caption := 'Patient Data';

  AMDITabBar.AddTab(frmChild);
end;
//****************************************************************************//
exports LoadDLLForm;

begin
  DLLProc := @DLLMain;
  DLLMain(DLL_PROCESS_ATTACH);
end.