在 Delphi 裡有一函數為 Pos, 它負責傳回出現在字串中第一個子字串的位置, 若無則傳回 0, 但是若我有 1..n 個相同子字串要搜尋, 則 Pos 無法滿足... 我查了一下 System.pas, pos 用 Assembly 寫的...嗚呼, 只好自己寫一個 function, 野人獻曝一下...請各位先進不吝指教, 謝謝

function PosFrom(const from: Integer; const substr: ShortString; const s: AnsiString): Integer;
var
  i, j, len: Integer;
  Found: boolean;
begin
  Result := 0;
  if from < 1 then
    Result := 0
  else if from > Length(s) then
    Result := 0
  else if Length(s) < Length(substr) then
    Result := 0
  else begin
    len := Length(substr);
    i := from;
    Found := False;
    while (not Found) and (i <= Length(s)) do
      for j:=1 to len do
        if substr[j] <> s[i] then begin
          inc(i, 1);
          break;
        end else begin
          inc(i, 1);
          if j = len then begin
            Result := i - len;
            Found := True;
            break;
          end;
        end; // end of if
  end;
end;

老兄， Delphi 带了一个 PosEx, 在 StrUtils.pas 里。help 里这样说：

function PosEx(const SubStr, S: string; Offset: Cardinal = 1): Integer;
Description

PosEx returns the index of SubStr in S, beginning the search at Offset. If Offset is 1 (default), PosEx is equivalent to Pos.

PosEx returns 0 if SubStr is not found, if Offset is greater than the length of S, or if Offset is less than 1.
===================引 用 文 章===================
在 Delphi 裡有一函數為 Pos, 它負責傳回出現在字串中第一個子字串的位置, 若無則傳回 0, 但是若我有 1..n 個相同子字串要搜尋, 則 Pos 無法滿足... 我查了一下 System.pas, pos 用 Assembly 寫的...嗚呼, 只好自己寫一個 function, 野人獻曝一下...請各位先進不吝指教, 謝謝

 function PosFrom(const from: Integer; const substr: ShortString; const s: AnsiString): Integer; var   i, j, len: Integer;   Found: boolean; begin   Result := 0;   if from < 1 then     Result := 0   else if from > Length(s) then     Result := 0   else if Length(s) < Length(substr) then     Result := 0   else begin     len := Length(substr);     i := from;     Found := False;     while (not Found) and (i <= Length(s)) do       for j:=1 to len do         if substr[j] <> s[i] then begin           inc(i, 1);           break;         end else begin           inc(i, 1);           if j = len then begin             Result := i - len;             Found := True;             break;           end;         end; // end of if   end; end;