Load forms as required.

[Marsheng]

Normally Delphi loads all the forms at runtime.

How do load forms only as needed ?

Eg

Form1 Connect to database
if Connected then load Form2

If I load form2 at the start, it tries to get data from a database that has not been opened as yet and crashes.

Thanks Wallace

[Norrit]

In the project manager right click on your project and select "view source"

Here you can remove all forms you don't want created, or change the order in which they do get created...
Now you can be as creative as you want with the rest (loading/creating the other forms)...

FYI: a form shouldn't connect to a database, a datamodule should

[Marsheng]

I need a form to be able to enter username and password.

Only the SQl connector is on the login form. All the tables are in the DM.

This is what I have - Probably not the best but Rome was not built in a day.

program Register;

uses
  Forms,
  uLogin in 'uLogin.pas' {fLogin},
  uDM in 'uDM.pas' {dm: TDataModule},
  uMain in 'uMain.pas' {fMain},
  uBikes in 'uBikes.pas' {fBikes},
  ... 
  uPrnMembers in 'uPrnMembers.pas' {fPrnMembers};

{$R *.res}

begin
  Application.Initialize;
  Application.CreateForm(TfLogin, fLogin);
  Application.CreateForm(Tdm, dm);
  Application.Run;
end.

on fLogin

procedure TfLogin.ConnectClick(Sender: TObject);
begin
   with MyRegister do begin
      Connected:=False;
      Port:=StrToInt(ePort.Text);
      Server:=eServer.Text;
      Username:=eUsername.Text;
      Database:=eDataBase.Text;
      Password:=ePassword.Text;
      try
        Connected:=True;
etc

procedure TfLogin.MyRegisterAfterConnect(Sender: TObject);
begin
   dm.tblEvent.Active:=True;
   dm.tblMembers.Active:=True;
   ......

   Application.CreateForm(TfMain, fMain);
   Application.CreateForm(TfBikes, fBikes);
   ..............
   fMain.Show;
end;

Messy but I'm a willing learner. How do I improve it ?

[Norrit]

program Register;

uses
  Forms,
  uLogin in 'uLogin.pas' {fLogin},
  uDM in 'uDM.pas' {dm: TDataModule},
  uMain in 'uMain.pas' {fMain},
  uBikes in 'uBikes.pas' {fBikes},
  ... 
  uPrnMembers in 'uPrnMembers.pas' {fPrnMembers};

{$R *.res}

begin
  Application.Initialize;
  Application.CreateForm(Tdm, dm);
  Application.CreateForm(TfLogin, fLogin);
  if dm.MyRegister.Connected then
    Application.Run;
end.

And in the fLogin call the dm.MyRegister component instead...
NB: Note that I also changed the creation order

[Marsheng]

Thanks I'll try your ideas tomorrow. It's late here in New Zealand. Cheers

[delphimpd]

Hi

You should read this page top to bottom, if you don't, you will mess up.

Get an new project and play with it, very simple and very useful

http://delphi.about.com/od/beginners/l/aa070203c.htm

Hope it helps

Good luck

Regards