private void btn_start_Click(object sender, EventArgs e)
        {
            //开始抽奖
            if (btn_start.Text == "停止")
            {
                timer1.Stop();
                btn_start.Text = "开始";

                //保存获奖信息
                SaveResult();
            }
            else
            {
                cjnum++;
                timer1.Start(); 
                
            }

        }

        private void SaveResult()
        {
            TGH.Lib.Log.WriteFile(Application.StartupPath + "\\choujiang.txt", "第" + cjnum.ToString() + "次抽奖数为:" + lbl_num.Text);
            lbl_result.Text += "第" + cjnum.ToString() + "次抽奖号码为:" + lbl_num.Text;// +"\r\n";
        }

        public int[] getRandomNum(int num, int minValue, int maxValue)
        {
            Random ra = new Random(unchecked((int)DateTime.Now.Ticks));
            arrNum = new int[num];
            int tmp = 0;
            for (int i = 0; i <= num - 1; i++)
            {
                tmp = ra.Next(minValue, maxValue); //随机取数
                arrNum[i] = ChouJiang(arrNum, tmp, minValue, maxValue, ra); //取出值赋到数组中
            }
            return arrNum;
        }


        private int ChouJiang(int[] cjresults, int tmp, int minnum, int maxnum, Random ra)
        {
            
            int i = 0;
            
            
            xunhuannum++;

            while (i <= cjresults.Length - 1)
            {
                if (cjresults[i] == tmp)
                {
                    //重新随即获取
                    tmp = ra.Next(minnum, maxnum);
                    //递归:如果取出来的数字和已取得的数字有重复就重新随机获取
                    ChouJiang(cjresults, tmp, minnum, maxnum, ra);
                }
                i++;
            }
            
            

            
            return tmp;
            
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            //从fw1至fw2中取出6个互不相同的随机数
            int[] arr = getRandomNum(cjtype, fw1, fw2); 
            int i = 0;
            string temp = "";
            while (i <= arr.Length - 1)
            {
                temp += arr[i].ToString() + "\n";
                i++;
            } 
            btn_start.Text = "停止";
            lbl_num.Text = temp;
        }

/// <summary>
        /// 生成最大值范围内无重复值的长度为最大值的随机序列,例：6，则返回0,1,2,3,4,5 的List
        /// </summary>
        /// <param name="maxValue"></param>
        /// <returns></returns>
        public static List<int> GetRandomList(this int maxValue)
        {
            if (maxValue == 0)
            {
                return null;
            }
            //逻辑描述：生成从0开始到maxValue的tempList
            //然后random一次就maxValue--，并将random出来的整数用做索引，加入到returnList并从tempList中移除
            maxValue = Math.Abs(maxValue);//防止负数
            List<int> tempList = new List<int>();
            for (int i = 0; i < maxValue; i++)
            {
                tempList.Add(i);
            }
            Random rd = new Random();
            List<int> returnList = new List<int>();
            while (maxValue > 0)
            {
                int tempInt = 0;
                if (maxValue > 1)//当maxValue为1时，不再进行随机，因为还剩一个数字，无需随机
                {
                    tempInt = rd.Next(maxValue);
                }
                returnList.Add(tempList[tempInt]);
                tempList.RemoveAt(tempInt);
                maxValue--;
            }

            return returnList;
        }

------解决方案--------------------