uses
  FMX.Platform.Android;

procedure TForm2.SpeedButton1Click(Sender: TObject);
begin
  MainActivity.finish;
end;

uses
  FMX.Platform.Android;

procedure TfrmMain.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  {退出程序}
  MainActivity.finish;
end;

procedure TfrmMain.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
  if MessageDlg('是否退出？', TMsgDlgType.mtConfirmation, [TMsgDlgBtn.mbOK, TMsgDlgBtn.mbCancel], -1) = mrOK then
    CanClose := true
  else
    CanClose := false;
end;

procedure TfrmMain.btncloseClick(Sender: TObject);
begin
  Close;
end;

 

procedure TfrmMain.FormKeyDown(Sender: TObject; var Key: Word;
  var KeyChar: Char; Shift: TShiftState);
begin

  //当按下硬件键盘的返回按钮时，关闭当前窗体
  if Key = vkHardwareBack then
    Close;
end;