1.安卓程序的退出询问和锁手机屏幕翻转

unit Unit1;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.StdCtrls;

type
  TForm1 = class(TForm)
    btn1: TButton;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure btn1Click(Sender: TObject);
    procedure FormKeyUp(Sender: TObject; var Key: Word; var KeyChar: Char;
      Shift: TShiftState);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.fmx}

uses
  FMX.Platform.Android;

{点击按钮退出}
procedure TForm1.btn1Click(Sender: TObject);
begin
  Close;
end;

{对话框的退出函数}
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
    {退出程序}
  MainActivity.finish;
end;

{退出前询问}
procedure TForm1.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;

{对话框创建}
procedure TForm1.FormCreate(Sender: TObject);
begin
{锁定屏幕不翻转}
  Application.FormFactor.Orientations := [TFormOrientation.soLandscape, TFormOrientation.soInvertedLandscape];
end;

{按下返回键}
procedure TForm1.FormKeyUp(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;

end.