Delphi7 流操作_压缩

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
btn1: TButton;
btn2: TButton;
edt1: TEdit;
btn3: TButton;
btn4: TButton;
procedure btn1Click(Sender: TObject);
procedure btn2Click(Sender: TObject);
procedure btn3Click(Sender: TObject);
procedure btn4Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}
uses Zlib;//delphi7 自带这Zlib.pas

//压缩
procedure TForm1.btn1Click(Sender: TObject);
var
cs:TCompressionStream;
fs,ms:TMemoryStream;
num:Integer;
begin
{第一步: 调入要压缩的文件, 并获取大小}
fs:=TMemoryStream.Create;
fs.LoadFromFile('a.fr3');
num:=fs.Size;

{第二步: 建立接收的流, 并先写入原始文件大小}
ms:=TMemoryStream.Create;
ms.Write(num,SizeOf(num));

{第三步: 压缩}
cs:=TCompressionStream.Create(clMax,ms); //压缩比例最大化，ms为接受流
fs.SaveToStream(cs); //保存流到压缩流
cs.Free; {压缩流 Free 后才真正完成压缩, 所以提前 Free}
ms.SaveToFile('a.zipx'); //delphi通过zlib压缩后生成的文件,winnar解压不了
ms.Free;
fs.Free;
end;

//解压缩
procedure TForm1.btn2Click(Sender: TObject);
var
ds: TDecompressionStream; {解压流}
fs,ms: TMemoryStream; {fs 是准备要解压的流; ms 是接受解压数据的流}
num: Integer; {接受文件压缩前的大小}
begin
{第一步: 准要解压的文件}
fs := TMemoryStream.Create;
fs.LoadFromFile('a.zipx'); {必须是上一个压缩方法生成的文件}

{第二步: 读出文件压缩前的大小}
fs.Position := 0;
fs.ReadBuffer(num,SizeOf(num));

{第三步: 准备好要接收的流, 并设置需要的大小}
ms := TMemoryStream.Create;
ms.SetSize(num);

{第四步: 解压}
ds := TDecompressionStream.Create(fs); {参数是要解压的流}

{第五步: 把解压后的数据读出存放到已准备好接收的流}
ds.Read(ms.Memory^, num);

{第六步: 保存}
ms.SaveToFile('b.fr3');

ds.Free;
ms.Free;
fs.Free;
end;

//序列化
procedure TForm1.btn3Click(Sender: TObject);
var
stream:TStream;
const
path='m.dat';
begin
stream:=TFileStream.Create(path,fmCreate);
stream.WriteComponentRes(edt1.ClassName,edt1); //写入资源到文件,edt1.ClassName可以为'xxx'等,可以随便命名
stream.Free;
end;

//反序列化
procedure TForm1.btn4Click(Sender: TObject);
var
stream:TStream;
const
path='m.dat';
begin
stream:=TFileStream.Create(path,fmOpenRead);
stream.ReadComponentRes(edt1); //读取资源到控件
stream.Free;
end;

end.