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.