unit1.~pas

通过流的方式对文件进行压缩和解压

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Gauges, StdCtrls, Buttons, ZLib, FileCtrl, StrUtils;

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Label1: TLabel;
    EditZipSource: TEdit;
    Label2: TLabel;
    EditZipSave: TEdit;
    BtnZipSource: TSpeedButton;
    btnZipSave: TSpeedButton;
    btnZip: TButton;
    PsZip: TGauge;
    GroupBox2: TGroupBox;
    Label3: TLabel;
    Label4: TLabel;
    btnUnZipSource: TSpeedButton;
    btnUnZipSave: TSpeedButton;
    PsUnZip: TGauge;
    EditUnZipSource: TEdit;
    EditUnZipSave: TEdit;
    btnUnZip: TButton;
    openZip: TOpenDialog;
    openUnZip: TOpenDialog;
    procedure BtnZipSourceClick(Sender: TObject);
    procedure btnUnZipSourceClick(Sender: TObject);
    procedure btnZipSaveClick(Sender: TObject);
    procedure btnUnZipSaveClick(Sender: TObject);
    procedure btnZipClick(Sender: TObject);
    procedure btnUnZipClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    procedure OnProgressZip(Sender: TObject);
  end;

var
  Form1: TForm1;
  FCompressStream   : TCompressionStream;    //压缩流
  FDecompressStream : TDecompressionStream;  //解压流
  FMemoryStream     : TMemoryStream;         //源内存流
  FZipMemoryStream  : TMemoryStream;         //目标内存流
  FSourceFileName   : String;                //压缩源文件名
  FZipFileName      : string;                //压缩文件名
  FUnZipFileName    : string;                //解压文件名
  i: integer = 0;

implementation

{$R *.dfm}

procedure TForm1.BtnZipSourceClick(Sender: TObject);
begin
  if openZip.Execute then
  begin
    EditZipSource.Text := openZip.FileName;
    FSourceFileName := ExtractFileName(openZip.FileName);
    FZipFileName := FSourceFileName+'.ZMP';
  end;
end;

procedure TForm1.btnUnZipSourceClick(Sender: TObject);
begin
  if openUnZip.Execute then
    EditUnZipSource.Text := openUnZip.FileName;
end;

procedure TForm1.btnZipSaveClick(Sender: TObject);
var
  s: string;
begin
  if SelectDirectory('选择压缩文件保存路径','',s) then
    EditZipSave.Text := s;
end;

procedure TForm1.btnUnZipSaveClick(Sender: TObject);
var
  s: string;
begin
  if SelectDirectory('选择解压文件保存路径','',s) then
  begin
    if Trim(EditUnZipSource.Text) = '' then
      exit;
    FUnZipFileName := AnsiReplaceText(ExtractFileName(EditUnZipSource.Text),'.ZMP','');
    EditUnZipSave.Text := s;
  end;
end;

procedure TForm1.btnZipClick(Sender: TObject);
var
  Size,x: integer;
  Time1,Time2,TheTime: double;
begin
  if (Trim(EditZipSource.Text) = '') or (Trim(EditZipSave.Text) = '') then
    exit;
  i := 0;
  FMemoryStream := TMemoryStream.Create;
  FZipMemoryStream := TMemoryStream.Create;
  try
    FMemoryStream.LoadFromFile(EditZipSource.Text);
    Size := FMemoryStream.Size;
    x := FZipMemoryStream.Write(size,sizeof(size)); //写入原始文件大小
    FCompressStream := TCompressionStream.Create(clDefault,FZipMemoryStream);
    try
      Time1 := GetTickCount;
      PsZip.Progress := 0;
      PsZip.MaxValue := size;    //此处不对
      FCompressStream.OnProgress := OnProgressZip;
      FMemoryStream.SaveToStream(FCompressStream);
    finally
      FCompressStream.Free;  //Free以后才算压缩成功，所以要先Free，再保存到文件
      Time2 := GetTickCount;
    end;
    FZipMemoryStream.SaveToFile(EditZipSave.Text+FZipFileName);
    ShowMessage(IntToStr(i)+#13#10+FloatToStr((Time2-Time1)/i)+#13#10+IntToStr(x));
  finally
    FMemoryStream.Free;
    FZipMemoryStream.Free;
  end;
end;

procedure TForm1.btnUnZipClick(Sender: TObject);
var
  Size: integer;
begin
  if (Trim(EditUnZipSource.Text) = '') or (Trim(EditUnZipSave.Text) = '') then
    exit;
  FMemoryStream := TMemoryStream.Create;
  FZipMemoryStream := TMemoryStream.Create;
  try
    FZipMemoryStream.LoadFromFile(EditUnZipSource.Text);
    FZipMemoryStream.Position := 0;         //复位指针
    FZipMemoryStream.ReadBuffer(Size,sizeof(Size));   //读出文件压缩前的大小
    FMemoryStream.SetSize(Size);    //设置需要的大小
    FDecompressStream := TDecompressionStream.Create(FZipMemoryStream);
    try
      FDecompressStream.Read(FMemoryStream.Memory^,Size);
    finally
      FDecompressStream.Free;
    end;
    FMemoryStream.SaveToFile(EditUnZipSave.Text+FUnZipFileName);
    ShowMessage('OK');
  finally
    FMemoryStream.Free;
    FZipMemoryStream.Free;
  end;
end;


procedure TForm1.OnProgressZip(Sender: TObject);
begin
  PsZip.Progress := PsZip.Progress + 1;
  i := i + 1;
end;

end.