1.一列数的规则如下: 1、1、2、3、5、8、13、21、34...... 求第30位数是多少， 用递归算法实现。

public class TuZi

    {

        public int TZ(int x)

        {

            if (x == 1 || x == 2)

            {

                return 1;

            }

            else

            {

                return TZ(x - 1) + TZ(x - 2);

            }

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            TuZi a = new TuZi();

            Console.WriteLine(a.TZ(12));

        }

    }

2.遍历页面上所有的textbox页面并将它赋值为string.empty?

foreach (System.Windows.Forms.Control item in this.Controls)

            {

                if (item is System.Windows.Forms.TextBox)

                {

                    System.Windows.Forms.TextBox tb = (System.Windows.Forms.TextBox)item;

                    tb.Text = string.Empty;

                }

            }

control类是所有控件的基类

3.实现一个冒泡排序算法

int[] arr = { 10, 29, 30, 40, 5 };

            for (int i = arr.Length; i >= 2;i-- )

            {

                for (int j = 0; j <i - 1;j++ )

                {

                    if (arr[j] < arr[j + 1])

                    {

                        int temp = arr[j + 1];

                        arr[j + 1] = arr[j];

                        arr[j] = temp;                  

                    }              

                }   

            }

            foreach (int item in arr)

            {

                Console.Write(item+" ");

                

            }

            Console.Read();