关于 Delphi 中流的使用(6) 用流读写结构化文件

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;



type

  TForm1 = class(TForm)

    Memo1: TMemo;     {添加 Memo 显示内容}

    Button1: TButton;

    Button2: TButton;

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



type

  TRec = record     {定义一个记录}

    name: string[8];

    age: Word;

  end;





//写入

procedure TForm1.Button1Click(Sender: TObject);

var

  rec: TRec;

  ms: TMemoryStream;

begin

  ms := TMemoryStream.Create;



  rec.name := '张三'; rec.age := 8;

  ms.Write(rec, SizeOf(rec));



  rec.name := '李四'; rec.age := 81;

  ms.Write(rec, SizeOf(rec));



  rec.name := '王二麻子'; rec.age := 18;

  ms.Write(rec, SizeOf(rec));



  ms.SaveToFile('c:\temp\rec.dat');



  ms.Free;

end;





//读取

procedure TForm1.Button2Click(Sender: TObject);

var

  rec: TRec;

  ms: TMemoryStream;

begin

  ms := TMemoryStream.Create;

  ms.LoadFromFile('c:\temp\rec.dat');



  Memo1.Clear;

  ms.Position := 0;

  while ms.Position < ms.Size do

  begin

    ms.Read(rec, SizeOf(rec));

    Memo1.Lines.Add(rec.name + ' ' + IntToStr(rec.age));

  end;

  {Memo1 的显示结果会是:

    张三 8

    李四 81

    王二麻子 18

  }



  ms.Free;

end;



end.