delphi 过滤开头 结尾 全部 空格的函数

function TrimAnsi(const S: AnsiString): Ansistring;
var
  I, L: Integer;
begin
  L := Length(S);
  I := 1;
  while (I <= L) and (S[I] <= ' ') do Inc(I);
  if I > L then Result := '' else
  begin
    while S[L] <= ' ' do Dec(L);
    Result := Copy(S, I, L - I + 1);
  end;
end;

function TrimLeftAnsi(const S: AnsiString): AnsiString;
var
  I, L: Integer;
begin
  L := Length(S);
  I := 1;
  while (I <= L) and (S[I] <= ' ') do Inc(I);
  Result := Copy(S, I, Maxint);
end;

function TrimRightAnsi(const S: Ansistring): AnsiString;
var
  I: Integer;
begin
  I := Length(S);
  while (I > 0) and (S[I] <= ' ') do Dec(I);
  Result := Copy(S, 1, I);
end;