delphi函数

 function ReplaceSub(str, sub1, sub2: String): String;
var
   aPos: Integer;
   rslt: String;
  begin
    aPos := Pos(sub1, str);
    //取得子字符串的位置
    rslt := '';
    while (aPos <> 0) do begin
      rslt := rslt + Copy(str, 1, aPos - 1) + sub2;
      Delete(str, 1, aPos + Length(sub1));
      //删除要替换的字符串
      aPos := Pos(sub1, str);
    end;
    Result := rslt + str;
    //添加要字符串
  end;