Please ask about the value transfer between two windows.

[zzzzzzz7]

I have two windows. Why does the 1st main window pass the value to the 2nd edit.text without error, but when I try use the 2nd window to pass the value to the 1st, it will report an error. Window 2: uses
  Classes, SysUtils, Form, Controls, Graphics, Dialogs, StdCtrls, Unit1; // <-unit1, an error will be reported here
------------------------------------------------------
unit2.pas(8,71) Error: Circular unit reference between Unit2 and Unit

[cdbc]

Hi
The 'Unit1' has to be moved from one 'uses' to another 'uses'...
Have a 'LookSee':

Code: Pascal  [Select][+][-]

1. uses   /// below unit1 is gone!!!
2.   Classes, SysUtils, Form, Controls, Graphics, Dialogs, StdCtrls;

instead you create a uses section in the implementation part of the unit2, like this:

Code: Pascal  [Select][+][-]

1. ...
2. implementation
3. uses Unit1;

That should take care of your /circular reference/ error...
Regards Benny

[zzzzzzz7]

//window 1

unit Unit1;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, StdCtrls, ExtDlgs,
  ExtCtrls, Grids, ComCtrls,Unit2, Menus;     //<--------------------------这里没报错   It's right

type

  { TForm1 }

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Edit4: TEdit;
    Edit5: TEdit;
    Image1: TImage;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    ListView1: TListView;
    MenuItem1: TMenuItem;
    PopupMenu1: TPopupMenu;
    SaveDialog1: TSaveDialog;
    Timer1: TTimer;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure DrawGrid1Click(Sender: TObject);
    procedure Edit1Change(Sender: TObject);
    procedure Edit3Change(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Image1Click(Sender: TObject);
    procedure Label3Click(Sender: TObject);
    procedure MenuItem1Click(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private

  public


  end;

var
  Form1: TForm1;

  st:string;
      f1_edit:string;
  f2_edit:string;
  a:boolean=true ;
  b:integer=0;

implementation

type
  rec =record
  name:string;
  sex:string;
  age:integer;
  end;

{$R *.lfm}

{ TForm1 }
procedure f( str1:string ; str2:string);
begin
    // TForm1.edit3.Text:=  inttostr( strtoint(str1)+strtoint(str2)) ;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  t1:string;
  t2:string;
  a:real;
  b:real ;
  c:real ;
begin
     t1:=edit1.Text;
     t2:=edit2.Text;
     a:=strtofloat(t1);
     b:=strtofloat(t2);
     c:=a+b;
     edit3.Text:=floattostr(c);

end;

procedure TForm1.Button2Click(Sender: TObject);
var
    tf:textfile;
  a:integer=911;
begin
     if savedialog1.Execute then
     begin
       assignfile(tf,savedialog1.FileName);
       rewrite(tf);
       write(tf,a);
       closefile(tf);
     end;

end;

procedure TForm1.Button3Click(Sender: TObject);
var
  str1:string='tttttt';
begin
     timer1.Interval:=5000;
    showmessage(str1);
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
  f1_edit:=edit4.Text;
  f2_edit:=edit5.Text;
 // form1.Hide;
  form2.f2Edit1.Text:=f1_edit;
  form2.f2Edit2.Text:=f2_edit;
end;



procedure TForm1.DrawGrid1Click(Sender: TObject);
begin

end;

procedure TForm1.Edit1Change(Sender: TObject);
begin

end;

procedure TForm1.Edit3Change(Sender: TObject);
begin

end;

procedure TForm1.FormCreate(Sender: TObject);
begin
        close;

end;

procedure TForm1.Image1Click(Sender: TObject);
begin

end;

procedure TForm1.Label3Click(Sender: TObject);
begin

end;

procedure TForm1.MenuItem1Click(Sender: TObject);
begin

end;

procedure TForm1.Timer1Timer(Sender: TObject);
var
  b:integer=254 ;
begin
  // if a=true then
  // image1.Top:=image1.Top+30
  // else
  // image1.Top:=image1.Top-30;
   while b>0 do
   begin
       image1.Top:=image1.Top-1  ;
       b:=b-1;
   end;
   //a:=not a;
end;

end.
                     

[zzzzzzz7]

unit Unit2;

{$mode ObjFPC}{$H+}

interface

uses
  Classes,SysUtils, Forms, Controls, Graphics, Dialogs,StdCtrls,Unit1; //<--这里报错 unit2.pas(8,70) Error: Circular unit reference between Unit2 and Unit1

type

  { TForm2 }

  TForm2 = class(TForm)
    Button1: TButton;
    F2Edit1: TEdit;
    f2Edit2: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private

  public

  end;

var
  Form2: TForm2;

implementation

{$R *.lfm}

{ TForm2 }

procedure TForm2.FormCreate(Sender: TObject);
begin

end;

procedure TForm2.Button1Click(Sender: TObject);
begin
 // F2Edit1.Text:=form1.Edit4.Text;
 // F2Edit2.Text:=form1.edit5.Text;
end;

end.
               
//-------unit2.pas(8,70) Error: Circular unit reference between Unit2 and Unit1

please help me       

[zzzzzzz7]

Hi
The 'Unit1' has to be moved from one 'uses' to another 'uses'...
Have a 'LookSee':

Code: Pascal  [Select][+][-]

1. uses   /// below unit1 is gone!!!
2.   Classes, SysUtils, Form, Controls, Graphics, Dialogs, StdCtrls;

instead you create a uses section in the implementation part of the unit2, like this:

Code: Pascal  [Select][+][-]

1. ...
2. implementation
3. uses Unit1;

That should take care of your /circular reference/ error...
Regards Benny

implementation
uses Unit1;//  unit2.pas(6,11) Error: Circular unit reference between Unit2 and Unit1 // the same

[dseligo]

Code: Pascal  [Select][+][-]

1. unit Unit2;
2.  
3. {$mode ObjFPC}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes,SysUtils, Forms, Controls, Graphics, Dialogs,StdCtrls; // Unit1 NOT HERE!
9.  
10. type
11.  
12.   { TForm2 }
13.  
14.   TForm2 = class(TForm)
15.     Button1: TButton;
16.     F2Edit1: TEdit;
17.     f2Edit2: TEdit;
18.     Label1: TLabel;
19.     Label2: TLabel;
20.     procedure Button1Click(Sender: TObject);
21.     procedure FormCreate(Sender: TObject);
22.   private
23.  
24.   public
25.  
26.   end;
27.  
28. var
29.   Form2: TForm2;
30.  
31. implementation
32.  
33. uses Unit1; // HERE!!!
34.  
35. {$R *.lfm}
36.  
37. { TForm2 }
38.  
39. procedure TForm2.FormCreate(Sender: TObject);
40. begin
41.  
42. end;
43.  
44. procedure TForm2.Button1Click(Sender: TObject);
45. begin
46.  // F2Edit1.Text:=form1.Edit4.Text;
47.  // F2Edit2.Text:=form1.edit5.Text;
48. end;
49.  
50. end.

[zzzzzzz7]

Code: Pascal  [Select][+][-]

1. unit Unit2;
2.  
3. {$mode ObjFPC}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes,SysUtils, Forms, Controls, Graphics, Dialogs,StdCtrls; // Unit1 NOT HERE!
9.  
10. type
11.  
12.   { TForm2 }
13.  
14.   TForm2 = class(TForm)
15.     Button1: TButton;
16.     F2Edit1: TEdit;
17.     f2Edit2: TEdit;
18.     Label1: TLabel;
19.     Label2: TLabel;
20.     procedure Button1Click(Sender: TObject);
21.     procedure FormCreate(Sender: TObject);
22.   private
23.  
24.   public
25.  
26.   end;
27.  
28. var
29.   Form2: TForm2;
30.  
31. implementation
32.  
33. uses Unit1; // HERE!!!
34.  
35. {$R *.lfm}
36.  
37. { TForm2 }
38.  
39. procedure TForm2.FormCreate(Sender: TObject);
40. begin
41.  
42. end;
43.  
44. procedure TForm2.Button1Click(Sender: TObject);
45. begin
46.  // F2Edit1.Text:=form1.Edit4.Text;
47.  // F2Edit2.Text:=form1.edit5.Text;
48. end;
49.  
50. end.

thank you very much! You are right !  Must be in the implementation

[Thaddy]

Yes, but as dseligo and cdbc explained: only one of them!
unit1 has unit2 in the interface section, unit2 has unit1 in the implementation section.

[zzzzzzz7]

Thank you all for your answers