Tips (1541)

Tip Bewertung (1):

{
Wenn Sie verschiedene Formular zentral initialisieren möchten
und dies mittels der Klassennamen erledigen möchten, dann
genügt folgendes...
Dabei können Sie auch allgemeine Aufgaben dazu erledigen...
}

{
If you'd like to zentralize Form creation only using class reference
information, then use the following...
You should do some generic jobs by the way, as shown in the example.
}

unit Unit2;

interface

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

{ Main Form declaration }
type
TForm2 = class(TForm)
btShowOneForm: TButton;
procedure btShowOneFormClick(Sender: TObject);
private
public
end;

var
Form2: TForm2;


{ extra stuff for the example...}

{
First, I declare some generic stuff to be available from all
of my automatic created forms: interface is the best
}
type
IMyGenericFormInterface = interface(IUnknown)
['{FDABF2E0-2279-11D6-9648-000374890932}']
function GetTitel: string;
property Titel: string read GetTitel;
end;
{
Then I can inflate the functionality of any of my declared
Form classes, adding a ref to my generic interface.
Notice: the function must be implemented in all the children
classes using he interface, but the main program doesn't care
what is there being done...just use it.
}

type
TMyFormTwo = class(TForm2, IMyGenericFormInterface)
private
function GetTitel: string;
end;
{
You have to register your form class using RegisterClasses
or to declare a variable of the given class so Delphi'll
do it for you...
}
var
MF2: TMyFormTwo;
{...END of extra stuff }

implementation

{$R *.dfm}


function TMyFormTwo.GetTitel: string;
begin
Result := 'Titel of 2. Form';
end;

{ !!! THIS is the "Global creation procedure" you should use !!! }
procedure ShowClassifiedForm(TheFormClass: TFormClass);
var
X: TForm;
begin
X := TheFormClass.Create(Application);
try
// Extra stuff: Check to see if TheFormClass
// can manage with Title
if Supports(X, IMyGenericFormInterface) then
ShowMessage((X as IMyGenericFormInterface).Titel);

X.ShowModal;
finally
X.Free;
end;
end;

procedure TForm2.btShowOneFormClick(Sender: TObject);
begin
//This will modal show a new copy a the Form2...
ShowClassifiedForm(TForm2);
//This will modal show an instance of a "TMyFormTwo" as a
//sub class of TForm2, thus showing the Titel at first...
ShowClassifiedForm(TMyFormTwo);
end;

end.