public void RandSort(int[] _num)
        {
            Random rd = new Random();
            int temp = 0, tempNum = 0;
            for (int i = 0; i < _num.Length-1; i++)
            {
                temp = rd.Next(i, _num.Length);
                tempNum=_num[i];
                _num[i] = _num[temp];
                _num[temp] = tempNum;
Thread.Sleep(20);//注意：引入命名空间：System.Threading;
            }
            string str = null;
            foreach (int item in _num)
            {
                str += item.ToString() + ",";
            }
            MessageBox.Show(str);
        }