How to Create a Popup Menu at Runtime

• Dec 28, 2020
• 2 minutes to read

In this example, we demonstrate how to create a popup menu from scratch at runtime. This sample requires a form with a TMemo control placed on it. The popup menu is created when a user right-clicks the memo control. The popup menu includes five items: “Cut”, “Copy”, “Paste”, “Clear”, and “Select All”. The PopupMenuButtonClick procedure processes a user’s selection of a given menu item. The Memo1MouseDown procedure represents the TMemo.OnMouseDown event handler.

Delphi

type
  TMainForm = class(TForm)
  private
    // ...
    procedure PopupMenuButtonClick(Sender: TObject);
    // ...
  end;
// ...
procedure TMainForm.PopupMenuButtonClick(Sender: TObject);
begin
  with Memo1 do
    case TdxBarButton(Sender).Tag of
      1: CutToClipboard;
      2: CopyToClipboard;
      3: PasteFromClipboard;
      4: ClearSelection;
      5: SelectAll;
    end;
end;
procedure TMainForm.Memo1MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
const
  ButtonCount = 5;
  Captions: array[1..ButtonCount] of string = ('Cu&t', '&Copy', '&Paste', 'Cle&ar', '&Select All');
var
  PopupMenu: TdxBarPopupMenu;
  I: Integer;
  Buttons: array[1..ButtonCount] of TdxBarButton;
begin
  if Button = mbRight then
  begin
    PopupMenu := TdxBarPopupMenu.Create(Self);
    for I := 1 to ButtonCount do
    begin
      Buttons[I] := TdxBarButton.Create(Self);
      with Buttons[I] do
      begin
        Caption := Captions[I];
        if I < ButtonCount then ImageIndex := I;
        Tag := I;
        OnClick := PopupMenuButtonClick;
      end;
      with PopupMenu.ItemLinks.Add do
      begin
        BeginGroup := I = ButtonCount;
        Item := Buttons[I];
      end;
    end;
    PopupMenu.PopupFromCursorPos;
    for I := 1 to ButtonCount do
      Buttons[I].Free;
    PopupMenu.Free;
  end;
end;

C++

Unit1.h
// ...
class TMainForm : public TForm
{
// ...
private:
  void __fastcall PopupMenuButtonClick(TObject *Sender);
// ...
};
Unit1.cpp
// ...
const int ButtonCount = 5;
const AnsiString Captions[ButtonCount] = {"Cu&t", "&Copy", "&Paste", "Cle&ar", "&Select All"};
void __fastcall TMainForm::PopupMenuButtonClick(TObject * Sender)
{
  switch( ((TdxBarButton *)Sender)->Tag )
  {
  case 1: Memo1->CutToClipboard(); break;
  case 2: Memo1->CopyToClipboard(); break;
  case 3: Memo1->PasteFromClipboard(); break;
  case 4: Memo1->ClearSelection(); break;
  case 5: Memo1->SelectAll(); break;
  }
}
void __fastcall TMainForm::Memo1MouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift, int X, int Y)
{
  TdxBarPopupMenu * PopupMenu;
  int I;
  TdxBarButton * Buttons[ButtonCount];
  TdxBarItemLink * NewItemLink;
  if (Button == mbRight)
  {
    PopupMenu = new TdxBarPopupMenu(this);
    for(I=0;I<ButtonCount;I++)
    {
      Buttons[I] = new TdxBarButton(this);
      Buttons[I]->Caption = Captions[I];
      if (I < ButtonCount-1)
        Buttons[I]->ImageIndex = I;
      Buttons[I]->Tag = I+1;
      Buttons[I]->OnClick = PopupMenuButtonClick;
      NewItemLink = PopupMenu->ItemLinks->Add();
      NewItemLink->BeginGroup = (I == ButtonCount);
      NewItemLink->Item = Buttons[I];
     }
    PopupMenu->PopupFromCursorPos();
    for(I=0;I<ButtonCount;I++)
      delete Buttons[I];
    delete PopupMenu;
  }
}