firedac数据集和字符串之间相互转换

firedac数据集和字符串之间相互转换

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92

/// <author>cxg 2018-12-20</author>   unit DatasetString;   interface   uses   System.NetEncoding, FireDAC.Stan.Intf, System.ZLib, System.Classes, FireDAC.Comp.Client,   System.SysUtils;   function DataSetToString(const ADataSet: TFDAdaptedDataSet): string;   function MemTableFromString(const AValue: string): TFDMemTable;   implementation   function DataSetToString(const ADataSet: TFDAdaptedDataSet): string; var   LBinary64: string;   LMemoryStream: TMemoryStream;   LStringStream: TStringStream;   LDstStream: TMemoryStream;   Zipper: TZCompressionStream; begin   LDstStream := TMemoryStream.Create;   try     LMemoryStream := TMemoryStream.Create;     try       ADataSet.SaveToStream(LMemoryStream, TFDStorageFormat.sfBinary);       LMemoryStream.Seek(0, TSeekOrigin.soBeginning);       Zipper := TZCompressionStream.Create(clDefault, LDstStream);       try         Zipper.CopyFrom(LMemoryStream, LMemoryStream.Size);       finally         Zipper.Free;       end;     finally       LMemoryStream.Free;     end;     LDstStream.Seek(0, TSeekOrigin.soBeginning);       LStringStream := TStringStream.Create;     try       TNetEncoding.Base64.Encode(LDstStream, LStringStream);       LBinary64 := LStringStream.DataString;     finally       LStringStream.Free;     end;   finally     LDstStream.Free;   end;   Result := LBinary64; end;   function MemTableFromString(const AValue: string): TFDMemTable; var   LMemTable: TFDMemTable;   LStringStream: TStringStream;   LMemoryStream: TMemoryStream;   LOrgStream: TMemoryStream;   Unzipper: TZDecompressionStream; begin   LMemTable := TFDMemTable.Create(nil);   LMemoryStream := TMemoryStream.Create;   try     LStringStream := TStringStream.Create(AValue);     try       LOrgStream := TMemoryStream.Create;       try         TNetEncoding.Base64.Decode(LStringStream, LOrgStream);         LOrgStream.Seek(0, TSeekOrigin.soBeginning);         Unzipper := TZDecompressionStream.Create(LOrgStream);         try           LMemoryStream.CopyFrom(Unzipper, Unzipper.Size);         finally           Unzipper.Free;         end;         LMemoryStream.Seek(0, TSeekOrigin.soBeginning);       finally         LOrgStream.Free;       end;     finally       LStringStream.Free;     end;     LMemTable.LoadFromStream(LMemoryStream, TFDStorageFormat.sfBinary);   finally     LMemoryStream.Free;   end;   Result := LMemTable; end;   end.