Mega Code Archive
How to put forms into a DLL
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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.
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