对于通过Byte数组进行文件操作的,在FTP中经常会使用到,我也是在Delphi调用Web Service进行文件的上传和下载时找到这两个函数的,挺好用的,推荐给大家。(申明:非本人所写)
1. 将Byte数组生成文件
procedure ByteArrayToFile(const ByteArray : TByteDynArray; const FileName : string );
var
 Count: integer;
 F: FIle of Byte;
 pTemp: Pointer;
begin
 AssignFile( F, FileName );
 Rewrite(F);
 try
    Count := Length( ByteArray );
    pTemp := @ByteArray[0];
    BlockWrite(F, pTemp^, Count );
 finally
    CloseFile( F );
 end;
end;
2. 将文件生成Byte数组
function FiIeToByteArray(const FileName:string ):TByteDynArray;
const
  BLOCK_SIZE=1024;
var
  BytesRead,BytesToWrite,Count:integer;
  F:File of Byte;
  pTemp:Pointer;
begin
  AssignFile( F, FileName );
  Reset(F);
  try
    Count := FileSize( F );
    SetLength(Result, Count );
    pTemp := @Result[0];
    BytesRead := BLOCK_SIZE;
    while (BytesRead = BLOCK_SIZE ) do
    begin
       BytesToWrite := Min(Count, BLOCK_SIZE);
       BlockRead(F, pTemp^, BytesToWrite , BytesRead );
       pTemp := Pointer(LongInt(pTemp) + BLOCK_SIZE);
       Count := Count-BytesRead;
    end;
  finally
     CloseFile( F );
  end;
end;