åµåµï¼æçæºåä¸æè¿ä¹ä¸ä¸ªå½æ°ãuses DUtils;// Left N characterfunction LeftStr(const S: String; n: Integer): String;// Right N characterfunction RightStr(const S: String; n: Integer): String;// Get a SubStrfunction SubStr(const S: String; Start, Len: Integer): String;