SQL 防止注入

var strsql = "insert into Staff_Answer (ExamTitleID,QuestionsID,MultipleChoice,RightOption,AnswerOption,IsRight,Score,StaffScore,Remark,State,Creator,CreatOrg,CreateTime) values";
        strsql += "(@ExamTitleID,@QuestionsID,@MultipleChoice,@RightOption,@AnswerOption,@IsRight,@Score,@StaffScore,@Remark,@State,@Creator,@CreatOrg,@CreateTime)";
        var cmd = new SqlCommand(strsql);
        var param = new SqlParameter[] {
                                                  new SqlParameter("@ExamTitleID",SqlDbType.UniqueIdentifier),
                                                  new SqlParameter("@QuestionsID",SqlDbType.UniqueIdentifier),
                                                  new SqlParameter("@MultipleChoice",SqlDbType.NVarChar,2),
                                                  new SqlParameter("@RightOption",SqlDbType.NVarChar,200),
                                                 new SqlParameter("@AnswerOption",SqlDbType.NVarChar,200),
                                                 new SqlParameter("@IsRight",SqlDbType.NVarChar,2),
                                                new SqlParameter("@Score",SqlDbType.Decimal,18),
                                                 new SqlParameter("@StaffScore",SqlDbType.Decimal,18),
                                                new SqlParameter("@Remark",SqlDbType.Text),
                                                 new SqlParameter("@State",SqlDbType.NVarChar,2),
                                                 new SqlParameter("@Creator",SqlDbType.NVarChar,200),
                                                 new SqlParameter("@CreatOrg",SqlDbType.NVarChar,200),
                                                 new SqlParameter("@CreateTime",SqlDbType.NVarChar,200)
                                             };

param[0].Value = new Guid(this.ExamTitleCode.Value);
        param[1].Value = new Guid(QuestionsID);
        param[2].Value = Anserdt.Rows[0]["MultipleChoice"].ToString();
        param[3].Value = RightOption;
        param[4].Value = AnswerOption;
        param[5].Value = ISRight ? "1" : "0";
        param[6].Value = Convert.ToInt32(Question.Rows[0]["Score"]);
        param[7].Value = ISRight ? Convert.ToInt32(Question.Rows[0]["Score"]) : 0;
        param[8].Value = this.Remark.InnerText;
        param[9].Value = "1";
        param[10].Value = userid;
        param[11].Value = Orgname1;
        param[12].Value = DateTime.Now;

foreach (SqlParameter para in param)
        {
            cmd.Parameters.Add(para);
        }
        helps.GetExecuteNonQueryBySqlPa(cmd);