本人经过两天的修改，做了进一步完善。各个方法功能逐步完善。但是鉴于自己水平有限，代码中错误还是比较多，代码冗余度还是偏高。欢迎大家提出意见，已供代码进一步完善。希望大家多多帮助。谢谢大家。2019年10月25日21点。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Drawing;
using System.Reflection;
using System.Net.NetworkInformation;
namespace play
{
class Program
{
//短期利率与长期利率
double lowRate = 0;
double highRate = 0;
//KeyValuePair<DateTime, >;
DateTime dt1 = new DateTime(2015, 3, 1);
DateTime dt2 = new DateTime(2015, 5, 11);
DateTime dt3 = new DateTime(2015, 6, 28);
DateTime dt4 = new DateTime(2015, 8, 26);
//贷款金额
static double totalMoney, balance;
static string choice;
static string newChoice;
//期数
int n;
//月供
double payMonth;
double rate;
double interest;
/// <summary>
/// 用来构建欢迎界面
/// </summary>
void Paint()
{
Console.WriteLine("***************************");
Console.WriteLine("***************************");
Console.WriteLine("***************************");
Console.WriteLine("欢迎使用房贷计算器");
Console.WriteLine("***************************");
Console.WriteLine("***************************");
Console.WriteLine("***************************");
Console.WriteLine("请按任意键继续");
Console.ReadKey();
Console.Clear();
}
/// <summary>
/// 按日期选择利率
/// </summary>
/// <param name="dt">输入的日期</param>
void RateChoose(DateTime dt)
{
if (dt >= dt4)
{
lowRate = 0.0275;
highRate = 0.0325;
}
else if (dt >= dt3)
{
lowRate = 0.03;
highRate = 0.035;
}
else if (dt >= dt2)
{
lowRate = 0.0325;
highRate = 0.0375;
}
else if (dt >= dt1)
{
lowRate = 0.035;
highRate = 0.04;
}
else
{
Console.WriteLine("你输入的日期不在范围内");
Console.ReadKey();
Environment.Exit(0);
}
}
/// <summary>
/// 计算月供
/// </summary>
void Payment(DateTime dt)
{
//设置缓冲区高度，即设置显示的最大行数
Console.BufferHeight = 1000;
RateChoose(dt);
switch (choice)
{
case "1":
{
//等额本息，月供计算方法
for (n = 1; n <= 360; n++)
{
if (n <= 60)
{
rate = lowRate;
}
else
{
rate = highRate;
}
//计算月供
double p;
p = rate / 12;
payMonth = (p * totalMoney * Math.Pow((1 + p), n)) / ((Math.Pow(1 + p, n) - 1));
//利息
interest = n * payMonth;
if (n % 2 == 0)
{
Console.ForegroundColor = ConsoleColor.Blue;
}
else
{
Console.ForegroundColor = ConsoleColor.White;
}
Console.WriteLine("{0}期按揭贷款的月供是{1:0.00}元，总利息是{2:0.00}元", n, payMonth, interest);
}
}
break;
case "2":
{
//等额本金，月供计算方法
for (n = 1; n <= 360; n++)
{
if (n <= 60)
{
rate = lowRate;
}
else
{
rate = highRate;
}
//计算月供
double p;
p = rate / 12;
payMonth = (totalMoney / n) + totalMoney * p;
interest = ((totalMoney / n + totalMoney * p) + totalMoney / n * (1 + p)) / 2 * n - totalMoney;
Console.WriteLine("{0}期按揭贷款的首月还款额是{1:0.00}元,总利息是{2:0.00}元", n, payMonth, interest);
}
}
break;
}
}
/// <summary>
/// 月贷计算方法
/// </summary>
/// <param name="n">还款期数</param>
void Compute(int n)
{
Console.WriteLine("期次 偿还利息 偿还本金 还款额 剩余本金");
switch (choice)
{
case "1":
//等额本息法计算房贷
{
if (n <= 60)
{
rate = lowRate;
}
else
{
rate = highRate;
}
double p;
p = rate / 12;
payMonth = (p * totalMoney * Math.Pow((1 + p), n)) / ((Math.Pow(1 + p, n) - 1));
for (int i = 1; i <= n; i++)
{
//string s = i.ToString();
interest = totalMoney * p;
double capital = payMonth - interest;
totalMoney -= capital;
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", i, interest, capital, payMonth, totalMoney);
}
}
break;
case "2":
//等额本金法计算房贷
{
if (n <= 60)
{
rate = lowRate;
}
else
{
rate = highRate;
}
double p;
p = rate / 12;
double capital = totalMoney / n;
for (int i = 1; i <= n; i++)
{
interest = totalMoney * p;
payMonth = capital + interest;
totalMoney -= capital;
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", i, interest, capital, payMonth, totalMoney);
}
}
break;
}
}
/// <summary>
/// 计算还款状况
/// </summary>
/// <param name="n0">还款期数</param>
/// <param name="dt">首次还款时间</param>
void Repayment(int n0, DateTime dt)
{
balance = totalMoney;
DateTime dt0 = dt;
double rate0;
double capital;
double p;
Console.WriteLine("还款时间 偿还利息 偿还本金 还款额 剩余本金");
switch (choice)
{
case "1":
{
RateChoose(dt0);
if (n0 <= 60)
{
rate0 = lowRate;
}
else
{
rate0 = highRate;
}
n = n0;
for (int i = 1; i <=n0; i++)
{
RateChoose(dt);
rate = (n0 <= 60 ? lowRate : highRate);
if (dt.Year != dt0.Year && rate != rate0)//这里应该有问题？
{
double p0 = rate0 / 12;
double payMonth0= (p0 * totalMoney * Math.Pow((1 + p0), n)) / ((Math.Pow(1 + p0, n) - 1));
double interest0 = balance * p0;
double capital0 = payMonth0 - interest0;
rate0 = rate;
interest = balance * (rate0/12);
totalMoney = balance;
balance -= capital0;
payMonth = capital0 + interest;
n =n0 - i+1;
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", dt, interest, capital0, payMonth, balance);
dt = dt.AddMonths(1);
continue;
}
p = rate0 / 12;
payMonth = (p * totalMoney * Math.Pow((1 + p), n)) / ((Math.Pow(1 + p, n) - 1));
interest = balance * p;
capital = payMonth - interest;
balance -= capital;
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", dt, interest, capital, payMonth, balance);
dt = dt.AddMonths(1);
}
}
break;
case "2":
{
RateChoose(dt0);
rate0 = (n0 <= 60 ? lowRate : highRate);
n = n0;
for (int i = 0; i < n0; i++)
{
RateChoose(dt);
rate = (n0 <= 60 ? lowRate : highRate);
if (dt.Year!=dt0.Year&&rate!=rate0)
{
rate0 = rate;
}
p = rate0 / 12;
capital = totalMoney / n0;
interest = balance * p;
payMonth = capital + interest;
balance -= capital;
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", dt, interest, capital, payMonth, balance);
dt = dt.AddMonths(1);
}
}
break;
}
}
/// <summary>
///实现提前还款功能
/// </summary>
/// <param name="n">还款总期数</param>
/// <param name="dt1">首次还款时间</param>
/// <param name="dt2">提前还款时间</param>
void Prepayment(int n0,DateTime dt1,DateTime dt2,double money)
{
balance = totalMoney;
DateTime dt0 = dt1;
double rate0;
double capital;
double p;
bool flag = false;
Console.WriteLine("还款时间 偿还利息 偿还本金 还款额 剩余本金");
switch (choice)
{
case "1":
{
RateChoose(dt0);
rate0 = (n0 <= 60 ? lowRate : highRate);
n = n0;
for(int i=1;i<=n0;i++)
{
RateChoose(dt1);
rate = (n0 <= 60 ? lowRate : highRate);
if (dt1.Year != dt0.Year && rate != rate0)//这里应该有问题？
{
double p0 = rate0 / 12;
double payMonth0 = (p0 * totalMoney * Math.Pow((1 + p0), n)) / ((Math.Pow(1 + p0, n) - 1));
double interest0 = balance * p0;
double capital0 = payMonth0 - interest0;
rate0 = rate;
interest = balance * (rate0 / 12);
totalMoney = balance;
balance -= capital0;
payMonth = capital0 + interest;
n = n0 - i + 1;
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", dt1, interest, capital0, payMonth, balance);
dt1 = dt1.AddMonths(1);
continue;
}
p = rate0 / 12;
if (dt2.Year == dt1.Year && dt2.Month == dt1.Month)
{
balance -= money;
totalMoney = balance;
switch (newChoice)
{
case "1":
{
n = n0 - i + 1;
flag = true;
}
break;
case "2":
{
double temp = Math.Log((payMonth / (payMonth - totalMoney * p)), (1 + p));
n= (int)Math.Ceiling(temp);
n0 = n + i - 1;
}
break;
}
}
payMonth = (p * totalMoney * Math.Pow((1 + p), n)) / ((Math.Pow(1 + p, n) - 1));
interest = balance * p;
capital = payMonth - interest;
balance -= capital;
if (flag)
{
payMonth += money;
capital += money;
flag = false;
}
Console.WriteLine("{0} {1:0.00} {2:0.00} {3:0.00} {4:0.00}", dt1, interest, capital, payMonth, balance);
dt1 = dt1.AddMonths(1);
}
}
break;
case "2":
{
}
break;
}
}
static void Main(string[] args)
{
{
Program p = new Program();
p.Paint();
Console.WriteLine("请选择您的操作！1.房贷计算 2.月供速算 3.还款状况 4.提前还款");
Console.WriteLine("请选择您的还款方式？1.等额本息 2.等额本金");
choice = Console.ReadLine();
Console.WriteLine("请输入你的贷款金额");
totalMoney = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("请输入您贷款的期数");
int number = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入你的首次贷款时间");
DateTime dT = Convert.ToDateTime(Console.ReadLine());
Console.WriteLine("请输入你的提前还款时间");
DateTime dTR = Convert.ToDateTime(Console.ReadLine());
Console.WriteLine("请输入你的还款金额");
double partMoney = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("请选择你要的后续操作！1.减少月供 2.缩短年限");
newChoice = Console.ReadLine();
//Console.WriteLine("你输入的日期是{0}，短期利率是{1}，长期利率是{2}",dT,p.lowRate,p.highRate);
//dT= dT.AddMonths(1);
// Console.WriteLine(dT);
// p.Repayment(number, dT);
// p.Compute(number);
// p.Payment(dTR);
p.Prepayment(number, dT, dTR, partMoney);
Console.ReadKey();
}
}
}
}