用zlib压缩解压,压缩没问题,解压老是出问题,怎么回事啊!!!!!!!!!!!!!!!帮我看看

Question

var
  FileName : string;
  ScrStream : TFileStream;  //   DestStream
  DestStream : TMemoryStream;
  Compress : TDecompressionStream;
  iCount: int64;
  Buffer : PChar;
begin
  if OpenDialog.Execute then
  begin
    FileName :=OpenDialog.FileName;
    ScrStream := TFileStream.Create(FileName,fmOpenRead);
    DestStream :=  TMemoryStream.Create;
    ScrStream.Position := 0;
    try      ScrStream.ReadBuffer(Buffer,iCount);
      GetMem(Buffer,iCount);      Compress := TDecompressionStream.Create(ScrStream);
      Compress.ReadBuffer(Buffer^,iCount);  ////在这就报错啊,怎么办,谁帮帮我啊      DestStream.WriteBuffer(Buffer^,iCount);
      DestStream.Position := 0;
     // if DestStream.Size > 0 then
      //DestStream.SaveToFile('test.exe');    finally
      ScrStream.Free;
      DestStream.Free;
    end;
  end;

Answer 1

//下面的语句是不是有错？
      ScrStream.ReadBuffer(Buffer,iCount); 
      GetMem(Buffer,iCount);
//改成如下：
iCount := ScrStream.Size + 1;
GetMem(Buffer,iCount);
ScrStream.ReadBuffer(Buffer,iCount); 

Answer 2

procedure TFilePacket.PackStream(var Stream: OleVariant);
var
  ZStream: TCompressionStream;
  InStream:TMemoryStream;
  TempStream:TMemoryStream;
  BStream:TMemoryStream;
  Param:OleVariant;
  p:Pointer;
  pi:Pointer;
  pj:Pointer;
  bSize:int64;
begin
  InStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  TempStream:=TMemoryStream.Create;
  pi:=VarArrayLock(Stream);
  try
     TempStream.Write(pi^,VarArrayHighBound(Stream,1)+1);
     ZStream:=TCompressionStream.Create(cldefault, InStream);
     try
        ZStream.CopyFrom(TempStream,0);
     finally
        ZStream.Free;
     end;
     Param:=VarArrayCreate([0,InStream.Size-1+sizeof(bSize)],varByte);
     p:=VarArrayLock(Param);
     try
        pj:=Addr(bSize);
        bSize:=TempStream.Size;
        BStream.Write(pj^,sizeof(bSize));
        BStream.Position:=sizeof(bSize);
        InStream.Position:=0;
        BStream.CopyFrom(InStream,InStream.Size);
        bstream.Position:=0;
        BStream.Read(p^,BStream.Size);
     finally
        VarArrayUnlock(Param);
     end;
  finally
     VarArrayUnlock(Stream);
     InStream.Free;
     TempStream.Free;
     BStream.Free;
  end;
  Stream:=Param;
end;
procedure TFilePacket.UnPackStream(var Stream: OleVariant);
var
  TempStream:TMemoryStream;
  OutStream:TMemoryStream;
  ZStream: TDecompressionStream;
  BStream:TMemoryStream;
  Param:OleVariant;
  p:Pointer;
  po:Pointer;
  bSize:int64;
  pj:Pointer;
begin
  TempStream:=TMemoryStream.Create;
  BStream:=TMemoryStream.Create;
  OutStream:=TMemoryStream.Create;
  p:=VarArrayLock(Stream);
  try
     TempStream.Write(p^,VarArrayHighBound(Stream,1)+1);
     pj:=Addr(bSize);
     TempStream.Position:=0;
     TempStream.Read(pj^,sizeof(bSize));
     TempStream.Position:=sizeof(bSize);
     if TempStream.Size>0 then BStream.CopyFrom(TempStream,TempStream.Size-sizeof(bSize));
     BStream.Position:=0;
     ZStream:=TDecompressionStream.Create(BStream);
     zstream.Position:=0;
     try
        OutStream.CopyFrom(ZStream,bSize);
        Param:=VarArrayCreate([0,OutStream.Size-1],varByte);
        po:=VarArrayLock(Param);
        try
           OutStream.Position:=0;
           OutStream.Read(po^,OutStream.Size);
        finally
           VarArrayUnlock(Param);
        end;
     finally
        ZStream.Free;
     end;
  finally
     VarArrayUnlock(Stream);
     BStream.Free;
     OutStream.Free;
     TempStream.Free;
  end;
  Stream:=Param;
end;

Answer 3

我的代码只是给你参考，单看你的解压代码是没有用的，需要看你是如何压缩的，即所谓的怎么存就怎么取，当然，在Zlib压缩时有一个麻烦事就是在保存压缩流时还须存入未压缩时的长度。