(*//标题:搜索字符串在流中的位置说明:适用于文件搜索等设计:Zswang支持:wjhu111@21cn.com日期:2004-03-21//*)(*//============================================================================设计思路:从流中将数据取到缓冲中再逐一对缓冲进行搜索============================================================================//*)function ScanStream(mStream: TStream; mStr: string): Integer;const cBufferSize = $8000;var S: string; T: string; I: Integer; L: Integer;begin Result := -1; if not Assigned(mStream) then Exit; if mStr = '' then Exit; L := Length(mStr); mStream.Position := 0; SetLength(S, cBufferSize); T := ''; for I := 1 to mStream.Size div cBufferSize do begin mStream.Read(S[1], cBufferSize); Result := Pos(mStr, T + S) - 1; //保留上次搜索的尾部字符～～ T := Copy(S, cBufferSize - L, MaxInt); if Result >= 0 then begin Result := Result + Pred(I) * cBufferSize - Length(T); Exit; end; end; I := mStream.Size mod cBufferSize; SetLength(S, I); if I > 0 then begin mStream.Read(S[1], I); Result := Pos(mStr, T + S) - 1; if Result >= 0 then begin Result := Result + mStream.Size - I - Length(T); Exit; end; end;end; { ScanStream }//Exampleprocedure TForm1.Button1Click(Sender: TObject);var vFileStream: TFileStream;begin vFileStream := TFileStream.Create('C:\temp\temp.exe', fmShareDenyNone); try Label1.Caption := IntToStr(ScanStream(vFileStream, Edit1.Text)); finally vFileStream.Free; end;end; |
