TPropertyPage.OnHide Event

Occurs when the form is hidden (that is, when its Visible property is set to false).

Pascal

property OnHide: TNotifyEvent;

C++

__property TNotifyEvent OnHide;

Description

Use OnHide to perform special processing when the form is hidden (that is, when the form's Visible property is set to false).

C++ Examples:

Copy Code

/*
This example uses two forms, each with a label and a button.
When the user clicks a button, the other form appears and
the current form disappears. Also, a message appears in the
label of the form that is showing, indicating that the other
form is hidden. Set the OnHide event handle for each form to
FormHide.This is the implementation section of Unit1:
*/
#include "TFormOnHide.h"
#include "Unit2.h"  // We must include unit2’s header file too!

#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;

__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}

void __fastcall TForm1::Button1Click(TObject *Sender)
{
  Form2->Show();
  Hide();
}

void __fastcall TForm1::FormHide(TObject *Sender)
{
  Form2->Label1->Caption = "Form1 is hiding";
}

Copy Code

/*
This is the implementation of Unit2:
*/
#include "Unit2.h"
#include "TFormOnHide.h"  // We must include unit1’s header file too!

#pragma package(smart_init)
#pragma resource "*.dfm"
TForm2 *Form2;

__fastcall TForm2::TForm2(TComponent* Owner)
    : TForm(Owner)
{
}

void __fastcall TForm2::Button1Click(TObject *Sender)
{
  Form1->Show();
  Hide();
}

void __fastcall TForm2::FormHide(TObject *Sender)
{
  Form1->Label1->Caption = "Form2 is hiding";
}

Delphi Examples:

Copy Code

{
This example uses two forms, each with a label and a button.
When the user clicks a button, the other form appears and
the current form disappears. Also, a message appears in the
label of the form that is showing, indicating that the other
form is hidden. Set the OnHide event handle for each form to
FormHide.This is the implementation section of Unit1:
}
 
implementation

{$R *.dfm}

uses Unit2;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Form2.Show;
  Hide;
end;

procedure TForm1.FormHide(Sender: TObject);
begin
  Form2.Label1.Caption := 'Form1 is hiding';
end;

Copy Code

{
This is the implementation section of Unit2:
}
implementation

{$R *.dfm}

uses TFormOnHide;

procedure TForm2.Button1Click(Sender: TObject);
begin
  Form1.Show;
  Hide;
end;

procedure TForm2.FormHide(Sender: TObject);
begin
  Form1.Label1.Caption := 'Form2 is hiding';
end;