c#编写贷款计算机程序源代码

在C#中编写一个简单的贷款计算器程序，我们可以创建一个名为`LoanCalculator`的类，其中包含一些基本的方法，如计算每月还款额、总利息等。以下是一个简化的示例：

using System;

public class LoanCalculator
{
    public double CalculateMonthlyPayment(double loanAmount, double interestRate, int years)
    {
        // 将年利率转换为月利率
        double monthlyInterestRate = interestRate / 1200;
        
        // 使用等额本息还款公式（PMT函数）
        double monthlyPayment = loanAmount * (monthlyInterestRate * Math.Pow(1 + monthlyInterestRate, years * 12)) / 
                                (Math.Pow(1 + monthlyInterestRate, years * 12) - 1);
        return monthlyPayment;
    }

    public double CalculateTotalInterest(double loanAmount, double interestRate, int years)
    {
        double monthlyPayment = CalculateMonthlyPayment(loanAmount, interestRate, years);
        double totalPayments = years * 12; // 总期数
        double totalInterest = totalPayments * monthlyPayment - loanAmount;
        return totalInterest;
    }
}

// 使用示例
public static void Main()
{
    double loanAmount = 50000; // 贷款金额
    double interestRate = 0.05; // 年利率
    int years = 5; // 贷款年限

    LoanCalculator calculator = new LoanCalculator();
    double monthlyPayment = calculator.CalculateMonthlyPayment(loanAmount, interestRate, years);
    double totalInterest = calculator.CalculateTotalInterest(loanAmount, interestRate, years);

    Console.WriteLine($"每月还款额：{monthlyPayment:C}");
    Console.WriteLine($"总利息：{totalInterest:C}");
}

这个程序定义了一个类`LoanCalculator`，包含了两个静态方法：`CalculateMonthlyPayment`用于计算每月还款额，`CalculateTotalInterest`用于计算总利息。在主方法`Main`中，我们实例化了`LoanCalculator`并调用了这两个方法。