Loan Calculator

 Design interface and implement functionalities for Loan calculator. Take Amount, No of installments and Rate of interest from the user. Also user can choose Early Pay option through a checkbox. Calculate installment amount using pmt() function. Do proper validation for inputs taken by the user.

Design:- 

Code:- 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using Microsoft.VisualBasic;

using System.Threading.Tasks;

namespace Loan_Calculator

{

    public partial class frmloancalculator : Form

    {

        public frmloancalculator()

        {

            InitializeComponent();

        }

        private void lblloancalculator_Click(object sender, EventArgs e)

        {

        }

        private void btncalculate_Click(object sender, EventArgs e)

        {

            double p = Convert.ToDouble(txtenteramount.Text);

            double r = Convert.ToDouble(txtenterrate.Text); 

            double n = Convert.ToDouble(txtentertime.Text);

            double M_payment;

            double T_payment;

            r = r / 100 / 12;//for Monthly Payment

            n = n * 12;//convert into Months

            M_payment= (p*r*(Math.Pow((1+r),n)))/((Math.Pow((1+r),n))-1);

            T_payment = (M_payment * n) - p;

            txttotalpayment.Text = Convert.ToString(T_payment);

            txtmonthlypayment.Text=Convert.ToString(M_payment);

        }

        private void btnreseat_Click(object sender, EventArgs e)

        {

            txttotalpayment.Text = "";

            txtmonthlypayment.Text = "";

            txtentertime.Text = "";

            txtenterrate.Text = "";

            txtenteramount.Text = "";

        }

        private void btnexit_Click(object sender, EventArgs e)

        {

            Application.Exit();

        }

        private void btnearlypaycalculate_Click(object sender, EventArgs e)

        {

            double p = Convert.ToDouble(txtenteramount.Text);

            double r = Convert.ToDouble(txtenterrate.Text);

            double n = Convert.ToDouble(txtentertime.Text);

            double monthly_rate = r / 1200;

            Double iamt;

            double FV=0;

            if (rbearlypay.Checked == true)

            {

                iamt = Financial.Pmt(monthly_rate,n,

                      -p, FV,

                        DueDate.BegOfPeriod); 

            }

            else

            {

                iamt = Financial.Pmt(monthly_rate, n,

                     -p, FV,

                       DueDate.EndOfPeriod);

            }

            txtpayment.Text=Convert.ToString(iamt);

        }

    }

}