关于 Delphi 中流的使用(4) 遍历读取流中的所有数据

unit Unit1;



interface



uses

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

  Dialogs, StdCtrls;



type

  TForm1 = class(TForm)

    Memo1: TMemo;

    Memo2: TMemo; {需要添加两个 Memo 用于显示}

    Button1: TButton;

    procedure Button1Click(Sender: TObject);

    procedure FormCreate(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



//先制造一个测试文件

procedure TForm1.FormCreate(Sender: TObject);

var

  strList: TStringList;

begin

  strList := TStringList.Create;

  strList.Add('ABCDEFGHIJKLMNOPQRSTUVWXYZ');

  strList.SaveToFile('c:\temp\test.txt');

  strList.Free;

end;





procedure TForm1.Button1Click(Sender: TObject);

var

  ms: TMemoryStream;

  c: Char;

  s1,s2: string;

begin

  ms := TMemoryStream.Create;

  ms.LoadFromFile('c:\temp\test.txt'); {读入内存流}



  s1 := '';

  s2 := '';

  ms.Position := 0;                       {指针到开始}

  while ms.Position < ms.Size do          {循环读出}

  begin

    ms.Read(c,1);                         {每读出一个字节, 指针会自动移到新的位置}

    s1 := s1 + c + ' ';                   {用文本记录}

    s2 := s2 + IntToHex(Byte(c),2) + ' '; {用两位数的十六进制记录}

  end;



  Memo1.Lines.Text := s1;

  Memo2.Lines.Text := s2;



  {Memo1 会显示: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z }

  {Memo2 会显示: 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 0D 0A}

  ms.Free;

end;



end.