unit U_CompressionFun;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ComCtrls, ToolWin, ShlObj, cxShellCommon, cxControls, cxContainer,
  cxShellTreeView, cxShellListView, StdCtrls, BtnEdit, OleCtnrs, DB, ADODB, ZLib;

procedure CompressionStream(var ASrcStream: TMemoryStream; ACompressionLevel: Integer = 2);

procedure UnCompressionStream(var ASrcStream: TMemoryStream);

procedure GetFileInfo(mFile: string; var mfileSize: integer; var CreationTime: tdatetime; var WriteTime: tdatetime);

function CovFileDate(Fd: _FileTime): TDateTime;

implementation

procedure GetFileInfo(mFile: string; var mfileSize: integer; var CreationTime: tdatetime; var WriteTime: tdatetime);
var
  vSearchRec: TSearchRec;
begin
  FindFirst(mFile, faAnyFile, vSearchRec);
  mfileSize := vSearchRec.Size;                                                             
  CreationTime := CovFileDate(vSearchRec.FindData.ftCreationTime); //创建时间
   //vSearchRec.FindData.ftLastAccessTime//访问时间
  WriteTime := CovFileDate(vSearchRec.FindData.ftLastWriteTime); //修改时间
  FindClose(vSearchRec);
end;

function CovFileDate(Fd: _FileTime): TDateTime;
var
  Tct: _SystemTime;
  Temp: _FileTime;
begin
  FileTimeToLocalFileTime(Fd, Temp);
  FileTimeToSystemTime(Temp, Tct);
  CovFileDate := SystemTimeToDateTime(Tct);
end;

////////////////////////////////////////////////////
///////压缩流
////////////////////////////////////////////////////
procedure CompressionStream(var ASrcStream: TMemoryStream; ACompressionLevel: Integer = 2);
var
  nDestStream: TMemoryStream;
  nTmpStream: TCompressionStream;
  nCompressionLevel: TCompressionLevel;
begin
  ASrcStream.Position := 0;
  nDestStream := TMemoryStream.Create;
  try
    //级别
    case ACompressionLevel of
      0:
        nCompressionLevel := clNone;
      1:
        nCompressionLevel := clFastest;
      2:
        nCompressionLevel := clDefault;
      3:
        nCompressionLevel := clMax;
    else
      nCompressionLevel := clMax;
    end;
    //开始压缩
    nTmpStream := TCompressionStream.Create(nCompressionLevel, nDestStream);
    try
      ASrcStream.SaveToStream(nTmpStream);
    finally
      nTmpStream.Free; //释放后nDestStream才会有数据
    end;
    ASrcStream.Clear;
    ASrcStream.LoadFromStream(nDestStream);
    ASrcStream.Position := 0;
  finally
    nDestStream.Clear;
    nDestStream.Free;
  end;
end;
////////////////////////////////////////////////////
///////解压缩流
////////////////////////////////////////////////////

procedure UnCompressionStream(var ASrcStream: TMemoryStream);
var
  nTmpStream: TDecompressionStream;
  nDestStream: TMemoryStream;
  nBuf: array[1..512] of Byte;
  nSrcCount: integer;
begin
  ASrcStream.Position := 0;
  nDestStream := TMemoryStream.Create;
  nTmpStream := TDecompressionStream.Create(ASrcStream);
  try
    repeat
      //读入实际大小
      nSrcCount := nTmpStream.Read(nBuf, SizeOf(nBuf));
      if nSrcCount > 0 then
        nDestStream.Write(nBuf, nSrcCount);
    until (nSrcCount = 0);
    ASrcStream.Clear;
    ASrcStream.LoadFromStream(nDestStream);
    ASrcStream.Position := 0;
  finally
    nDestStream.Clear;
    nDestStream.Free;
    nTmpStream.Free;
  end;
end;

end.