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Silly question...

Posted on 2003-11-17
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Last Modified: 2010-04-05
Hello,

I know i'm gonna get laughed at me... but can anyone tell me how to reference a RichEdit component from the main Form of an MDI App. where RichEdit is on the MDI Child form??? thanks alot!!!
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Question by:Prototype_T-104
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14 Comments
 
LVL 26

Expert Comment

by:EddieShipman
ID: 9764817
Say your MDIChild is named Child2...

  Child2.RichEdit1

should do it...

0
 
LVL 2

Expert Comment

by:sgc_romania
ID: 9764818
MainForm.ActiveMDIChild.richedit1
0
 
LVL 26

Expert Comment

by:EddieShipman
ID: 9764854
Suppose it is NOT the Active child???
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LVL 27

Expert Comment

by:kretzschmar
ID: 9764897
TFormClassWithRichedit(ActiveMDIChild).richedit1

or

TFormClassWithRichedit(MDIChildren[index]).richedit1

whereas
TFormClassWithRichedit is the Class declaration od your MDIChild

meikl ;-)
0
 
LVL 27

Expert Comment

by:kretzschmar
ID: 9764905
typo
od -> of
0
 

Author Comment

by:Prototype_T-104
ID: 9766693
hmmm i am still getting error: "Undeclared identifier : RichEdit1".
I don't get it...
0
 
LVL 26

Expert Comment

by:EddieShipman
ID: 9766910
You must include the unit that contains the MDIChild in your implementation uses clause.
From the Main Menu, select File->Use Unit and select the unit that contains the MDIChild
that contains the RichEdit.
0
 
LVL 12

Expert Comment

by:andrewjb
ID: 9770341
Eddie's will work.
sgc_romana's wont.
kretzschmar's will, too, so long as you use the right class name(!)

Sounds like you're using Eddie's method.
0
 
LVL 27

Expert Comment

by:kretzschmar
ID: 9770403
a sample

--- main-unit

unit mdi_re_main_u;

interface

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

type
  TForm1 = class(TForm)
    Panel1: TPanel;
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses mdi_re_child_u;  //child-unit used

procedure TForm1.Button1Click(Sender: TObject);
begin
  with TForm2.Create(self) do show;
end;

procedure TForm1.Button2Click(Sender: TObject);
var i, childs, lines : integer;
begin
  childs := MDIChildCount;
  lines := 0;
  for i := 0 to MDIChildCount -1 do
    if (MDIChildren[i] is TForm2) then
      lines := lines + TForm2(MDIChildren[i]).RichEdit1.Lines.Count;

  Showmessage('There are '+inttostr(childs)+' Childs'+#10+
              'Which are Containing in Sum '+inttostr(lines)+' Lines Text');

end;

end.

---- Child-Unit
unit mdi_re_child_u;

interface

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

type
  TForm2 = class(TForm)
    RichEdit1: TRichEdit;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  action := caFree;
end;

end.

---------

meikl ;-)
0
 

Author Comment

by:Prototype_T-104
ID: 9770678
Thanks but here is what i need. When i press a button on the toolbar, i want "You pressed button1..." or any other text to be displayed in the RichEdit1 of the Active MDIChild (something like ActiveMDIChild.RichEdit1.Add('sdkfsdh')- only it doesn't work).  Thanks very much for even reading up to here and i know i am very boring but i can't get this to work.
0
 
LVL 27

Accepted Solution

by:
kretzschmar earned 400 total points
ID: 9770709
...
begin
  //just use the conversion (TForm2 is the childformClass here)
  if (ActiveMDIChild is TForm2) then
    TForm2(ActiveMDIChild).RichEdit1.Add('sdkfsdh');
end;

meikl ;-)
0
 
LVL 12

Expert Comment

by:andrewjb
ID: 9770723
You can't do it directly that way. 'ActuveMDIChid' is a TForm. A TForm doesn't have a RichEdit1 component. So you can't do it generically.

Either:

Derive all your MDI child forms from some base class which _does_ have a RichEdit1 component.

Then you could do

TBaseMDIForm( ActiveMDIChlid ).RichEdit1.Add('asldkajslkd');

or, check to see which class the Active chlid is..

if ActiveMDIChild is TFirstChlidForm then
  TFirstChildForm(ActiveMDIChild).RicheEdit1.Add('asdasd');
else if ActiveMDIChlid is TSecondChildForm then
  TSecondChlidForm(...)...
else ...

etc.

depending on how many chlid form class types you've got.

0
 
LVL 12

Expert Comment

by:andrewjb
ID: 9770736
NB "You can't do it directly that way" applies to T-104's last comment, not meikl's !

0
 

Author Comment

by:Prototype_T-104
ID: 9770833
Thanks alot guys you helped me alot!! it works now!!!
0

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