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Создание или управление формами по названию класса



Оформил: DeeCo

{ 
Wenn Sie verschiedene Formular zentral initialisieren mцchten 
und dies mittels der Klassennamen erledigen mцchten, dann 
genьgt folgendes... 
Dabei kцnnen 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.





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