ASP.NET中的类App_Code中的局部类

Question

I created a class for connection and using with register.aspx without any problem. When i try to move codes from register.aspx.cs to regpartial.cs then i get an conflict error: "connection conn = new connection();"

I would like to move codes register.aspx.cs to mypartial.cs. I think it will be better but i'm not sure how can i solve conflict problem.

Register.aspx.cs (final)

using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Web.UI;
using System.Web.UI.WebControls;
using test.App_Code;


namespace test
{   
    public partial class register: System.Web.UI.Page
    {
        private void Page_Load(object sender, EventArgs e)
        {

        }

Connection.cs (final try)

using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI.WebControls;

namespace test.App_Code
{
    public class connection
    {

        public SqlConnection connect()
        {
            SqlConnection conn= new SqlConnection("Data Source=******;Initial Catalog=****;Integrated Security=False;User Id=****;Password=*****;MultipleActiveResultSets=True");
            baglanti.Open();
            return (conn);
        }
}

regpartial.cs (Final try)

using System;
using System.Data;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Web.UI;
using System.Web.UI.WebControls;


namespace test.App_Code.partials
{
    connection conn = new connection();
    public partial class regpartial : register
    {

    }
}

Answer 1

In general you shouldn't have much code inside your aspx.cs files.

You want to separate the logic that is directly your view/presentation logic (stuff that makes the .aspx pages work) from your business logic (sequencing, transformation, validation), and finally you want to have your Data Access / Resource Access to be isolated.

I'd also recommend using Dapper.NET over raw ADO.NET/SqlConnection.

I'm going to string together a very basic example of how you can separate this. This is not guaranteed to compile c# code but it will very close pseudocode.

Inside registration.aspx.cs

private void btnRegister_Click(object sender, EventArgs e)
{
    var email = txtEmail.Text;
    var password = txtPassword.Text;

    var registration = new Registration { Email = email, Password = password }

    var bizService = new RegistrationService();

    var response = bizService.Register(registration);

    if(response.Success) Response.Redirect("~/registration/success");

    ltlError.Text = response.FailureMessage;

}

RegistrationService.cs

public class RegistrationService {

    public RegistrationResponse Register(Registration req)
    {
        var regDAL = new RegistrationAccess();

        var isEmailDuplicated = regDal.DoesEmailExist(req.Email)

        if(isEmailDuplicated) 
              return new RegistrationResponse { 
                    Success = false,
                    FailureMessage = "Email exists, did you mean to login instead? 
                }

        regDAL.InsertNewRegistration(req)

        return new RegistrationResponse { Success = true };   
    }
}

Lastly you should have a RegistrationAccess.cs that contains only code for reading and writing to SQL Server / other database / file system.

Note how the aspx.cs file has no knowledge of RegistrationAccess. Your view should not be directly calling the database. The other thing to note is that RegistrationService has no knowledge of the view. It receives a Registration type, then executes business logic and calls out to the DAL. The DAL class will have zero knowledge of both the view and the RegistrationService, it will know only one thing, the database.

This is the basis of a very simple ASP.NET webforms solution. A better solution would use the MVP/MVVM patterns and the Dependency Inversion Principle but those aren't worth using if you don't understand basic separation of concerns yet.