Live Razor Page Samples

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using System.ComponentModel.DataAnnotations;

namespace Website.Pages.Support.Samples.RazorPages.Calculations
{
    public partial class AmortizationCalculatorModel : PageModel
    {
        [BindProperty]
        [StringLength(25)]
        [Display(Name = "Loan Amount")]
        public string LoanAmount { get; set; }

        [BindProperty]
        [StringLength(25)]
        [Display(Name = "Interest Rate")]
        public string InterestRate { get; set; }

        [BindProperty]
        [Range(1, 360)]
        [Display(Name = "Total # of Periods")]
        public int Periods { get; set; }

        public string PaymentAmount { get; set; } = "Run Sample";

        public string LastPayment { get; set; } = "Run Sample";

        public string TotalInterest { get; set; } = "Run Sample";

        // This range will be used to populate the header row in the HTML table.
        public SpreadsheetGear.IRange HeaderRange { get; set; }

        // This range will be used to populate the data HTML table.
        public SpreadsheetGear.IRange DataRange { get; set; }


        public void OnGet()
        {
            LoanAmount = "$15,000";
            InterestRate = "7.25%";
            Periods = 24;
        }

        public IActionResult OnPost()
        {
            if (!ModelState.IsValid)
            {
                SetErrorMessage("Error occurred while running sample.  Please correct the errors shown below.");
                return Page();
            }

            // Open the workbook
            SpreadsheetGear.IWorkbook workbook = SpreadsheetGear.Factory.GetWorkbook("files/amortization.xlsx");

            // Get IRanges for cells from defined names.
            SpreadsheetGear.IRange pv = workbook.Names["pv"].RefersToRange;
            SpreadsheetGear.IRange rate = workbook.Names["rate"].RefersToRange;
            SpreadsheetGear.IRange nper = workbook.Names["nper"].RefersToRange;

            // Copy the form values to the worksheet.
            pv.Formula = LoanAmount;
            rate.Formula = InterestRate;
            nper.Formula = Periods;

            // Display payment and interest details
            PaymentAmount = workbook.Names["Payment"].RefersToRange.Text;
            LastPayment = workbook.Names["LastPayment"].RefersToRange.Text;
            TotalInterest = workbook.Names["TotalInterest"].RefersToRange.Text;

            // Return the IRange used for the specified defined name, in this case the populated portion of the
            // amortization table, including the header row.
            SpreadsheetGear.IRange table = workbook.Names["AmortizationTableForNPer"].RefersToRange;

            // Provide specific IRanges for the header and data areas of the table for easier consumption by the view.
            HeaderRange = table[0, 0, 0, table.ColumnCount - 1];
            DataRange = table[1, 0, table.RowCount - 1, table.ColumnCount - 1];

            return Page();
        }
    }
}