辛亥百年纪念 - 产品组件系列05

于 2011-10-18 11:25:00 发布 · 77 阅读

本文介绍了一个使用Delphi开发的COM组件，该组件主要用于读取和写入FCN文件，并计算文件的CRC32校验值。文章提供了完整的源代码实现，包括生成CRC32表的方法、计算指定文件CRC32值的函数以及读写FCN文件的过程。

“天下为公”

---------------------------

《COM组件》

此组件目的：可供VB调用的COM。

此组件用途：读/写FCN文件

==Code=========

FCN.dpr

(*-------------------------------------------------------------------------- Delphi菜鸟XiaoBin 2006.5.31于黑龙江草甸子 http://blog.youkuaiyun.com/xiaobin_hlj80 veic_2005@163.com --------------------------------------------------------------------------*) unit UCRC32; interface uses Windows, SysUtils, Classes, Udefine; type CRC32array=array[0..255]of Longint; var crc32table:CRC32array; procedure generateCRC32Array; function calculateCRC32Number(filePath1:PChar):DWORD;stdcall; procedure saveFCNFile(saveFile1,CheckFilePath:pchar);stdcall; function readFCNFile(loadFile1:PChar):DWORD;stdcall; implementation procedure generateCRC32Array; var i11,j22,crc:longword; begin for i11:=0 to 256 do begin crc:=i11; for j22:=0 to 8 do begin if (crc and 1)=1 then begin crc:=(crc shr 1)xor $EDB88320; end else begin crc:=crc shr 1; end; end; crc32table[i11]:=crc; end; end; function calculateCRC32Number(filePath1:PChar):DWORD; var crc32:DWORD; len:longword; i1:integer; fs:TFileStream; Buffer: array[1..8192] of Byte; begin generateCRC32Array; try fs:=TFileStream.Create(filePath1,fmOpenRead); len:=fs.Read(Buffer,sizeof(Buffer)); crc32:=$ffffffff; for i1:=1 to len do begin crc32:=((crc32 shr 8)and $ffffff)xor crc32table[(crc32 xor dword(Buffer[i1]))and $ff]; end; finally fs.Free; end; Result:=crc32; end; procedure saveFCNFile(saveFile1,CheckFilePath:Pchar); var fileStream1:TFileStream; begin DeleteFile(saveFile1); If Not FileExists(saveFile1) Then Begin try fileStream1:= TFileStream.Create(saveFile1, fmCreate); FileHead.Version := '1.9.8.0'; FileHead.author:='xiaobin'; FileHead.CRC32:=calculateCRC32Number(CheckFilePath); Filehead.UpdateDate := Now; fileStream1.Write(FileHead, SizeOf(FileHead)); finally fileStream1.Free; end; End; end; function readFCNFile(loadFile1:PChar):DWORD;stdcall; var fileStream2:TFileStream; begin try fileStream2:=TFileStream.Create(loadFile1,fmOpenRead); fileStream2.Read(FileHead,sizeof(FileHead)); Result:=FileHead.CRC32; finally fileStream2.Free; end; end; end.