Delphi XE2 之 FireMonkey 入门(33) - 控件基础: TFmxObject: SaveToStream、LoadFromStream、SaveToBinStream、LoadFromBinStream

SaveToStream()、LoadFromStream() 对应文本流;
SaveToBinStream()、LoadFromBinStream() 对应二进制流; 相对文本流, 二进制流会小一些.

有这几个方法, 控件数据与状态的序列化就太容易了.

示例:
1、控件: ListBox1、Button1、Button2
2、事件: Button1.OnClick、Button2.OnClick、Form1.OnCreate

---

unit Unit1;

interface

uses

  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,

  FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs, FMX.Layouts, FMX.ListBox;

type

  TForm1 = class(TForm)

    ListBox1: TListBox;

    Button1: TButton;

    Button2: TButton;

    procedure FormCreate(Sender: TObject);

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

  end;

var

  Form1: TForm1;

implementation

{$R *.fmx}

{给 ListBox1 加点内容}

procedure TForm1.FormCreate(Sender: TObject);

var

  i: Integer;

begin

  for i :=  to  do

    ListBox1.Items.Add('Item' + IntToStr(i));

end;

{存取 ListBox1}

procedure TForm1.Button1Click(Sender: TObject);

const

  path = 'c:\temp\ListBox1Stream.txt';

var

  stream: TFileStream;

begin

  {1}

  stream := TFileStream.Create(path, fmCreate);

  ListBox1.SaveToStream(stream);

  stream.Free;

  {2}

  ListBox1.Clear;

  ShowMessage('a');

  {3}

  stream := TFileStream.Create(path, fmOpenRead);

  ListBox1.LoadFromStream(stream);

  stream.Free;

end;

{存取当前窗体}

procedure TForm1.Button2Click(Sender: TObject);

const

  path = 'c:\temp\Form1Stream.dat';

var

  stream: TFileStream;

begin

  {1}

  stream := TFileStream.Create('c:\temp\Form1Stream.dat', fmCreate);

  Self.SaveToBinStream(stream);

  stream.Free;

  {2}

  Button1.Free;

  Button2.Free;

  ListBox1.Free;

  Realign;

  ShowMessage('a');

  {3}

  stream := TFileStream.Create('c:\temp\Form1Stream.dat', fmOpenRead);

  Self.LoadFromBinStream(stream);

  stream.Free;

end;

end.

---

状态保存测试:
1、控件: Button1、Button2、Panel1; 在 Panel1 中再放三个 TCheckBox
2、事件: Button1.OnClick、Button2.OnClick、Form1.OnCreate、Form1.OnDestroy

---

unit Unit1;

interface

uses

  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,

  FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs;

type

  TForm1 = class(TForm)

    Panel1: TPanel;

    CheckBox1: TCheckBox;

    CheckBox2: TCheckBox;

    CheckBox3: TCheckBox;

    Button1: TButton;

    Button2: TButton;

    procedure FormCreate(Sender: TObject);

    procedure FormDestroy(Sender: TObject);

    procedure Button2Click(Sender: TObject);

    procedure Button1Click(Sender: TObject);

  end;

var

  Form1: TForm1;

implementation

{$R *.fmx}

var

  stream: TMemoryStream;

procedure TForm1.FormCreate(Sender: TObject);

begin

  stream := TMemoryStream.Create;

  Button2.Enabled := False;

end;

procedure TForm1.FormDestroy(Sender: TObject);

begin

  stream.Free;

end;

{调整三个 CheckBox 的状态后保存}

procedure TForm1.Button1Click(Sender: TObject);

begin

  Panel1.SaveToStream(stream);

  ShowMessage(IntToStr(stream.Size));

  Button2.Enabled := True;

end;

{恢复}

procedure TForm1.Button2Click(Sender: TObject);

begin

  stream.Position := ;

  Panel1.LoadFromStream(stream);

end;

end.