TMenuItems (Delphi)

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Description

This example demonstrates how to add and delete menu items to a pop-up menu at run time and assign an event handler to the OnClick event. Place a TPopupMenu and three buttons on the form named "AddButton", "EditButton", and "DestroyButton" and add OnClick events to all three buttons. Put the TPopupMenu in the PopupMenu property of the form. Place the PopupMenuItemsClick procedure in the TForm1 type declaration so that it can be used as the method call for the menu item OnClick event.

Code

type
  TForm1 = class(TForm)
    AddButton: TButton;
    EditButton: TButton;
    DestroyButton: TButton;
    PopupMenu1: TPopupMenu;
    procedure AddButtonClick(Sender: TObject);
    procedure EditButtonClick(Sender: TObject);
    procedure DestroyButtonClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    procedure PopupMenuItemsClick(Sender: TObject);

  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.AddButtonClick(Sender: TObject);
var
  index: Integer;
  NewItem: TMenuItem;
begin
	// The owner (PopupMenu1) will clean up this menu item.
  NewItem := TMenuItem.Create(PopupMenu1); // Create the new item.
  index := PopupMenu1.Items.Count;
  PopupMenu1.Items.Add(NewItem);// Add it to the pop-up menu.
  NewItem.Caption := 'Menu Item ' + IntToStr(index);
  NewItem.Tag := index;
  NewItem.OnClick :=
    PopupMenuItemsClick; // Assign it an event handler.
end;

procedure TForm1.PopupMenuItemsClick(Sender: TObject);
begin
  with Sender as TMenuItem do
  begin
    case Tag of
      0:  ShowMessage('first item clicked');
      1:  ShowMessage('second item clicked');
      2:  ShowMessage('third item clicked');
      3:  ShowMessage('fourth item clicked');
    end;
  end;
end;

{
To edit or destroy an item, grab its pointer 
using the Items property.
procedure TForm1.EditButtonClick(Sender: TObject);
var
  ItemToEdit: TMenuItem;
begin
  ItemToEdit := PopupMenu.Items[1];
  ItemToEdit.Caption := 'Changed Caption';
end;

procedure TForm1.DestroyButtonClick(Sender: TObject);
var
  ItemToDelete: TMenuItem;
begin
  ItemToDelete := PopupMenu.Items[2];
  ItemToDelete.Free;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
  index: Integer;
  NewItem: TMenuItem;
begin
  for index := 0 to 3 do
  begin
	  // The owner (PopupMenu1) will clean up this menu item.
    NewItem := TMenuItem.Create(PopupMenu1); // Create the new item.
    PopupMenu1.Items.Add(NewItem);// Add it to the pop-up menu.
    NewItem.Caption := 'Menu Item ' + IntToStr(index);
    NewItem.Tag := index;
    NewItem.OnClick :=
      PopupMenuItemsClick; // Assign it an event handler.
  end;
end;

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