How-to-put-forms-into-a-DLL


            Title: How to put forms into a DLL?
Question: How to put forms into a DLL?
Answer:
Create a new Project. Define the following procedure type
TMyProc = procedure(App : TApplication; Scr : TScreen); stdcall;
In the "private" area of "TForm1" add
MyDLLHandle : THandle;
ShowMyModuleForm : TMyProc;
Add a "Form1.OnCreate" event and add this code to it:
MyDLLHandle:=LoadLibrary('Project2.DLL');
if MyDLLHandle0
then @ShowMyModuleForm:=GetProcAddress(MyDLLHandle,'ShowMyForm')
else ShowMyModuleForm:=nil;
Add a "Form1.OnDestroy" event and add this code to it
if Assigned(ShowMyModuleForm) then 
 ShowMyModuleForm:=nil;
if MyDLLHandle 0 then
 FreeLibrary(MyDLLHandle);
MyDLLHandle:=0;
Now drop a "TButton" onto the form and add an "OnClick" event with this code
if (MyDLLHandle0) and (Assigned(ShowMyModuleForm)) then 
 ShowMyModuleForm(Application,Screen);
That's all for the EXE side. Create a new project (library project)
{$R *.res}
procedure ShowMyForm(App : TApplication; Scr : TScreen); stdcall;
var
 a: TForm2;
begin
 Application := App;
 Screen := Scr;
 a := TForm2.Create(Application.MainForm);
 {"Application.MainForm" could also be "nil" or any valid value}
 a.ShowModal;
 a.Free;
end;
exports
ShowMyForm;
end.
Add to the "uses" clause "Forms". Add a new form unit to the project. In the 
"Implementation" area of the form put:
var
 OldApp : TApplication;
 OldScr : TScreen;
initialization
 OldApp := Application;
 OldScr := Screen;
finalization
 Screen := OldScr;
 Application := OldApp;
end.
Put a "TButton" on the new form and set the "ModalResult" to "mrOk". Compile the 
"dll" and the "exe". There's a sample form in DLL.
If you already have a form made that you want in the DLL just use it instead of 
"TForm2". Make sure the "initialization" and "finalization" code is in one, and 
only one, of the forms you put into the DLL. Without that code you may get 
unexpected results.
System Delphi
