delphi进制转换源码

delphi中有直接把10进制转换成16进制的函数：
  function   IntToHex(Value:   Integer;   Digits:   Integer):   string;   overload; 
  function   IntToHex(Value:   Int64;   Digits:   Integer):   string;   overload;
 

unit uConversion;

interface
uses
SysUtils,Math;
type
TConversion = class
public
    //10 进制 to 2,8,16 进制
    function inttoBitStr(intstr: string): string;
    function IntToHexStr(intStr: string): String;//10 = 2
    function IntToOStr(intstr : string): string;
    //2进制 to 10,8,16 进制
    function BittoInt(BitStr:   String):   LongInt;// 2 = 10
    function BitStrToHextStr(const   BitStr   :   String)   :   String;//2 = 16
    function BitStrToOStr(const   BitStr   :   String)   :   String;//2 = 8
    //16 > 10 2   8 进制
    function HextoIntStr(HexStr: String): string;
    function HexToBitStr(HexStr:   string): string;
    function HexToOStr(HexStr:   string): string;
 
    //八进制转换成二进制字符串
    function OtoBitStr(O : string):string;
    function OtoIntStr(O : string):string;
    function OtoHexStr(O : string):string;

end;
var
TC :TConversion;

implementation
{ TConversion }
//2 进制 to 10 进制
function TConversion.BittoInt(BitStr: String): LongInt;
var
      i,Size:   Integer;
begin
      Result:=0;
      Size:=Length(BitStr);
      for   i:=Size   downto   1   do
      begin
        //例如 1010
          if Copy(BitStr,i,1)='1'   then
            Result:=Result+(1   shl   (Size-i));
      end;
//第二种方法
//二进制转换为十进制 start
{
VAR
str : String;
Int : Integer;
i : integer;
Str := UpperCase(Edit1.Text);
Int := 0;
FOR i := 1 TO Length(str) DO
    Int := Int * 2 + ORD(str[i]) - 48;