Communicating between frames in Delphi - delphi

Question

I just started using Frames in Delphi.
That Frames are in FrameBar1 and they both are visible. Just for testing, first one contains one Button and second Frame contains one Edit.
I want to change text in Edit with click on Button (which are controls on two different frames).
How to communicate between frames?

Answer 1

The same way you would if the controls were in the same Form. Just prefix the Edit control with the Frame object that owns it, eg:
uses
Frame1Unit, Frame2Unit;
procedure TForm1.FormCreate(Sender: TObject);
begin
Frame1 := TFrame1.Create(Self);
Frame1.Parent := ...;
...
Frame2 := TFrame2.Create(Self);
Frame2.Parent := ...;
...
end;
uses
Frame2Unit;
procedure TFrame1.Button1Click(Sender: TObject);
begin
Frame2.Edit1.Text := '...';
end;
A better design would be to encapsulate the logic so Frame1 and Frame2 do not know about each other. Have Frame1 expose an event that it fires when the button is clicked, and then the parent Form can assign a handler to that event and assign the text on the Frame2, eg:
uses
Frame1Unit, Frame2Unit;
procedure TForm1.FormCreate(Sender: TObject);
begin
Frame1 := TFrame1.Create(Self);
Frame1.Parent := ...;
Frame1.OnNewText := Frame1Text;
...
Frame2 := TFrame2.Create(Self);
Frame2.Parent := ...;
...
end;
procedure TForm1.Frame1Text(Sender: TObject; const NewText: string);
begin
Frame2.EditText := NewText;
end;
type
TFrame1TextEvent = procedure(Sender: TObject; const NewText; string) of object;
TFrame1 = class(TFrame)
Button1: TButton;
procedure Button1Click(Sender: TObject);
public
OnNewText: TFrame1TextEvent;
end;
procedure TFrame1.Button1Click(Sender: TObject);
begin
if Assigned(OnNewText) then
OnNewText(Self, '...');
end;
type
TFrame2 = class(TFrame)
Edit1: TEdit;
private
function GetEditText: string;
procedure SetEditText(const Value: string);
public
property EditText: string read GetEditText write SetEditText;
end;
function TFrame2.GetEditText: string;
begin
Result := Edit1.Text;
end;
procedure TFrame2.SetEditText(const Value: string);
begin
Edit1.Text := Value;
end;