delphi 转 C#

const
MODS:tmods=('ke3wms','jnx9i8','dpqzl6','vyg1bh','7a4c2f','u5rto0');//不清楚这个是什么数据类型？
SDOM:tmods=('wa6j1c','fblrk7','mg9q0s','vu3zth','po4xy2','ni5d8e');
DOMS:tmods=('mg9qwc','vu3zth','a6j10s','fbk7lr','5dpoy2','4xni8e');

function discryptpassword(apassword:string):string;
var tmpi,i:integer;
begin
result:=lattertosixstr(apassword,sdom);
if length(result)<3 then
begin
result:='';
exit;
end;
tmpi:=0;
for i:=1 to 3 do
tmpi:=tmpi*6+strtoint(result[i]);
result:=copy(result,4,tmpi);
result:=sixstrtolatter(result,mods);
end;


function lattertosixstr(astr:string;amods:tmods):string;
var i,n,p:integer;tmps1,tmps2:string;
begin
tmps1:='';
tmps2:='';
for i:=1 to length(astr) do
begin
for n:=1 to 6 do
begin
p:=pos(astr[i],amods[n]);
if p>0 then
begin
tmps1:=tmps1+inttostr(n-1);
tmps2:=inttostr(p-1)+tmps2;
break;
end;
end;
end;
result:=tmps1+tmps2;
end;

function sixstrtolatter(astr:string;amods:tmods):string;
var i,n:integer;
begin
result:='';n:=length(astr);
if (n mod 2)=1 then exit;//求余
for i:=1 to (n div 2) do //求商
begin
result:=result+amods[ord(astr[i])-ord('0')+1][ord(astr[n-i+1])-ord('0')+1];
end;
end;