p;     Stream[0] := #76;
            EncLine := Stream+#13#10;
            Encoded.Write(EncLine, Length(EncLine));
            Quads := 0;
        end;
    end;
    {“=”补位}
    if (Decoded.Size mod 3) = 2 then
    begin
        Decoded.Read(B, 2);
        Stream[Quads+1] := _Code64[(B[0] div 4)+1];
        Stream[Quads+2] := _Code64[(B[0] mod 4)*16 + (B div 16)+1];
        Stream[Quads+3] := _Code64[(B mod 16)*4 + 1];
        Stream[Quads+4] := ''='';
        Inc(Quads, 4);
    end;

    if (Decoded.Size mod 3) = 1 then
    begin
        Decoded.Read(B, 1);
        Stream[Quads+1] := _Code64[(B[0] div 4)+1];
        Stream[Quads+2] := _Code64[(B[0] mod 4)*16 + 1];
        Stream[Quads+3] := ''='';
        Stream[Quads+4] := ''='';
        Inc(Quads, 4);
    end;

    Stream[0] := Chr(Quads);
    if Quads > 0 then
    begin
        EncLine := Stream+#13#10;
        Encoded.Write(EncLine, Length(EncLine));
    end;

    Result := Encoded.Size;
end;