在 c# 和 mvc 中的类之间传递数据表

Question

Its been awhile I have been programming in c# and have a question about creating a data table in a class and then trying to access that datatable from another class or mvc controller. Some advice and some explanation would be much appreciated

Current class

using OfficeOpenXml;
using System;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using ppms_excel.Models;



namespace ppms_excel.Models
{

    public class PODataTable
    {

        public DataTable LDataTable
        {
            get
            {
                DataTable legalEntityTable = new DataTable("legal_entitiy");
                legalEntityTable.Columns.Add("Id", typeof(int));
                legalEntityTable.Columns.Add("ExternalId", typeof(string));
                legalEntityTable.Columns.Add("Source", typeof(string));
                legalEntityTable.Columns.Add("XpressEntityId", typeof(int));
                legalEntityTable.Columns.Add("EntityTypeId", typeof(int));
                legalEntityTable.Columns.Add("EntityName", typeof(string));
                legalEntityTable.Columns.Add("EIN", typeof(string));
                legalEntityTable.Columns.Add("Descripton", typeof(string));
                legalEntityTable.Columns.Add("Address1", typeof(string));
                legalEntityTable.Columns.Add("Address2", typeof(string));
                legalEntityTable.Columns.Add("City", typeof(string));
                legalEntityTable.Columns.Add("State", typeof(string));
                legalEntityTable.Columns.Add("PostalCode", typeof(string));
                legalEntityTable.Columns.Add("WebSiteUrl", typeof(string));
                legalEntityTable.Columns.Add("PricingAgreementTime", typeof(DateTimeOffset));
                legalEntityTable.Columns.Add("AgreementTime", typeof(DateTimeOffset));
                legalEntityTable.Columns.Add("AgreementSoourceIP", typeof(string));
                legalEntityTable.Columns.Add("CustomerServiceEmail", typeof(string));
                legalEntityTable.Columns.Add("CustomerServicePhoneNumber", typeof(string));
                legalEntityTable.Columns.Add("Active", typeof(bool));
                legalEntityTable.Columns.Add("TimeZone", typeof(string));
                legalEntityTable.Columns.Add("CreateTime", typeof(DateTimeOffset));
                legalEntityTable.Columns.Add("RiskToken", typeof(string));
                legalEntityTable.Columns.Add("DBA", typeof(string));
                legalEntityTable.Columns.Add("YearOfFormation", typeof(string));
                legalEntityTable.Columns.Add("DateOfFormation", typeof(string));


                return legalEntityTable;
            }
        }
    }
}

Controller

    using Microsoft.AspNetCore.Hosting;
    using Microsoft.AspNetCore.Mvc;
    using Microsoft.Extensions.Logging;
    using OfficeOpenXml;
    using ppms_excel.Models;
    using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Diagnostics;
    using System.Linq;
    using System.Threading.Tasks;
    using System.IO;
    using Excel = Microsoft.Office.Interop.Excel;
    
    
    namespace ppms_excel.Controllers
    {
        public class LoadDataTableController1 : Controller
        {
            public IActionResult Index()
            {
    
                //var x=new PODataTable().LDataTable.TableName;
                
                
                ExcelPackage ld = new ExcelPackage();
                
    
    
                ExcelWorksheet worksheet = ld.Workbook.Worksheets.FirstOrDefault();
                if (worksheet == null)
                {
                    //return or alert message here
                }
                else
                {
    
                    
    
                    var colcount= worksheet.Dimension.Columns;
                    string[] coltitle = new string[colcount];
                    for (int i = 1; i <= colcount; i++)
                    {
                        coltitle[i - 1] = (string) worksheet.Cells[1, i].Value;
                    }
    
    
    
    
                       //read excel file data and add data in  model.StaffInfoViewModel.StaffList
                           var rowCount = worksheet.Dimension.Rows;
                           var colCount = worksheet.Dimension.Columns;
                           **PODataTable Le = new PODataTable().LDataTable;**
    
    
                  
                }
                return View();
            }
        }
    }

is this the correct way to get the datatable instantiated in the controller? PODataTable Le = new PODataTable().LDataTable;

thanks

Answer 1

Sure, there are many ways to solve this. In general, it's always a good idea to separate controller logic from model or utility logic, like you have done. The reference to ppms_excel.Models will allow you to use that class just like you have it.

In general, I would be careful about using properties for building and passing back more complicated objects. This can lead to poor performance since the object will be recreated each time. If possible, store the built object in a local variable of the utility class and return that instead. This will prevent unnecessary recreates (if it will be the same each time).