uses Windows;

function NormalizedStrLen(const S: String): SmallInt;//System.Length возвращает SmallInt

implementation

const
//  NormalizationOther = 0;
 NormalizationC     = 1;
//  NormalizationD     = 2;
//  NormalizationKC    = 5;
//  NormalizationKD    = 6;

function IsNormalizedString(NormForm: Integer; lpString: LPCWSTR;
 cwLength: Integer): BOOL; stdcall; external 'Normaliz.dll';
function NormalizeString(NormForm: Integer; lpSrcString: LPCWSTR; cwSrcLength: Integer;
 lpDstString: LPWSTR; cwDstLength: Integer): Integer; stdcall; external 'Normaliz.dll';

function NormalizedStrLen(const S: String): SmallInt;
var Buf: String;
begin
 if not IsNormalizedString(NormalizationC, PChar(S), -1) then
 begin
   SetLength(Buf, NormalizeString(NormalizationC, PChar(S), Length(S), nil, 0));
   Result := NormalizeString(NormalizationC, PChar(S), Length(S), PChar(Buf), Length(Buf));
 end
 else
   Result := Length(S);
end;
end.

function UnicodeToAnsiString(const ws:string; codePage: Word): AnsiString;
var
 l: integer;
begin
 if ws = ' then
   Result := '
 else
 begin
   l := WideCharToMultiByte(codePage,
     WC_COMPOSITECHECK or WC_DISCARDNS or WC_SEPCHARS or WC_DEFAULTCHAR,
     @ws[1], - 1, nil, 0, nil, nil);
   SetLength(Result, l - 1);
   if l > 1 then
     WideCharToMultiByte(codePage,
       WC_COMPOSITECHECK or WC_DISCARDNS or WC_SEPCHARS or WC_DEFAULTCHAR,
       @ws[1], - 1, @Result[1], l - 1, nil, nil);
 end;
end;

//d2009,2010,XE
var
su:string;// not downwards portable for Delphi versions < d2009
sa:AnsiString;
begin
//ansi to unicode is automatic:
sa:='Test';
su:= su; //compiler will do conversion.
// but warning generated: implicit conversion unicode to ansi

// unicode to ansi needs helper function:
sa:= UnicodeToAnsiString(su,1251{cp russian});

end;

program test; //DPR, not in units
{$DEFINE UNICODE_CTRLS}

//d2009,2010,XE
var
u,a:integer;
su:string;// not downwards portable for Delphi versions < d2009
sa:AnsiString;
begin
sa:='Test';
su:= su; //compiler will do conversion.
u:=length(su);// <mile>
a:=length(sa);

end;

uses
 windows,
 kol;

function UnicodeToAnsiString(const ws: WideString; codePage: Word): AnsiString;
 overload;
var
 l: integer;
begin
 if ws = '' then
   Result := ''
 else
 begin
   l := WideCharToMultiByte(codePage,
     WC_COMPOSITECHECK or WC_DISCARDNS or WC_SEPCHARS or WC_DEFAULTCHAR,
     @ws[1], -1, nil, 0, nil, nil);
   SetLength(Result, l - 1);
   if l > 1 then
     WideCharToMultiByte(codePage,
       WC_COMPOSITECHECK or WC_DISCARDNS or WC_SEPCHARS or WC_DEFAULTCHAR,
       @ws[1], -1, @Result[1], l - 1, nil, nil);
 end;
end;

function UnicodeToAnsiString(const ws: WideString; codePage: Word): AnsiString;
 overload;
begin
 Result := UnicodeToAnsiString(ws, GetACP);
end;

//still sleepy clipboard
function UnicodeToAnsiString(const ws: WideString): AnsiString;overload;
begin
Result := UnicodeToAnsiString(ws, GetACP);
end;