刚学C#，还不怎么会写程序！！！请大家帮忙编一个小程序把计算附件里的公式，要求保留小数点后8位。谢谢啦。

仅供参考：
using System;
using System.Collections.Generic;
using
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace Formula
{
    public partial class Form1 : Form
    {
        public bool X = false;
        public bool N = false;
        public Form1()
        {
            InitializeComponent();
            bt_calculate.Enabled = false;
        }

        private int doMutiN(int n)
        {
            int total = 1;
            for (int i = n; i >= 1; i--)
            {
                total *= i;
            }
            return total;
        }
        private void bt_calculate_Click(object sender, EventArgs e)
        {
            int n = Convert.ToInt16( textBox_N.Text);
            double x = Convert.ToSingle(textBox_X.Text);
            double result = 1 + x - Math.Pow(x, 2) / doMutiN(2) + Math.Pow(x, 3) / doMutiN(3) + Math.Pow(-1, n + 1) * Math.Pow(x, n) / doMutiN(n);
            textBox_result.Text =  result.ToString("f8");
        }
        private void doCheck_X_N()
        {
            if (X & N)
            {
                bt_calculate.Enabled = true;
            }
        }


        private void textBox_N_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (!char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar))
            {
                e.Handled = true;
            }
            if(textBox_N.Text!="")
            {
                N = true;
            }
            doCheck_X_N();
        }

        private void textBox_X_KeyPress_1(object sender, KeyPressEventArgs e)
        {
            if (!char.IsDigit(e.KeyChar) && !char.IsPunctuation(e.KeyChar) && !char.IsControl(e.KeyChar))
            {
                e.Handled = true;
            }
            if (textBox_X.Text != "")
            {
                X = true;
            }
            doCheck_X_N();
        }
      
    }
}

太长了吧！！！！我才刚学C#啊！！！这只是一道小作业题！！！

其实，这里面private void textBox_N_KeyPress(object sender, KeyPressEventArgs e)和private void textBox_X_KeyPress_1(object sender, KeyPressEventArgs e)是保证两个textbox里面输入的都是数字，而不是字母，在两个textbox都有输入的情况下，计算才可用。如果不用这两个事件，程序在输入都是数字的情况下也是可以执行的。

我们才开始用控制台应用程序。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace calculate
{
    class Program
    {
        private static int doMutiN(int n)
        {
            int total = 1;
            for (int i = n; i >= 1; i--)
            {
                total *= i;
            }
            return total;
        }

        static void Main(string[] args)
        {
            Console.WriteLine("Please input N:");
            int n = Convert.ToInt16(Console.ReadLine());
            Console.WriteLine("Please input X:");
            double x = Convert.ToDouble(Console.ReadLine());
            double result = 1 + x - Math.Pow(x, 2) / doMutiN(2) + Math.Pow(x, 3) / doMutiN(3) + Math.Pow(-1, n + 1) * Math.Pow(x, n) / doMutiN(n);
            Console.WriteLine("The result:"+result.ToString("f8"));
            Console.ReadLine();

        }
    }
}
这次应该可以吧？！

呵呵，麻烦了您了！谢谢啦！！

Console.WriteLine("The result:"+result.ToString("f8"));
呵呵，就这一句代码就可以确定精确的位数了，我还以为要编一些代码才行呢！！！不可思议！！请问：result.ToString("f8")这是什么意思啦，为什么出来一个f8啊！！

你可以从MSDN的tostring（）方法看看他的帮助，好像“f8”就是留8位小数。

f8相当于flost 保留8位小数。flost表示单精度