将复杂对象保存到会话 ASP .NET CORE 2.0

Question

我对 ASP .NET 核心很陌生，所以请帮忙。我想避免 ASP .NET 核心应用程序的数据库往返。我有在数据网格中动态添加列的功能。列设置（可见性、启用、宽度、标题）存储在 DB 中。

所以我想在服务器上存储List<,PersonColumns> 仅用于实际会话。但我无法做到这一点。我已经使用 JsonConvert 方法对会话中的对象进行序列化和反序列化。这适用于List<,Int32>或具有简单属性的对象，但不适用于具有嵌套属性的复杂对象。

我想存储到会话的对象如下所示：

[Serializable]
  public class PersonColumns
  {
    public Int64 PersonId { get; set; }
    List<ViewPersonColumns> PersonCols { get; set; }

    public PersonColumns(Int64 personId)
    {
      this.PersonId = personId;
    }

    public void LoadPersonColumns(dbContext dbContext)
    {
      LoadPersonColumns(dbContext, null);
    }

    public void LoadPersonColumns(dbContext dbContext, string code)
    {
      PersonCols = ViewPersonColumns.GetPersonColumns(dbContext, code, PersonId);
    } 

    public static List<ViewPersonColumns> GetFormViewColumns(SatisDbContext dbContext, string code, Int64 formId, string viewName, Int64  personId)
    {
      var columns = ViewPersonColumns.GetPersonColumns(dbContext, code, personId);

      return columns.Where(p => p.FormId == formId && p.ObjectName == viewName).ToList();
    }


  }

我还想问一下，我的方法是将 600 条记录的列表保存到会话中是否不错？每次用户想要显示网格时访问数据库和加载列是否更好？

任何建议表示赞赏

谢谢

编辑：我已经测试存储在会话List<,ViewPersonColumns> 中并且它被正确保存。当我保存List<,ViewPersonColumns>为属性的对象时，只保存内置类型，List 属性为空。

我想在会话中保存的对象

[Serializable]
  public class UserManagement
  {
    public String PersonUserName { get; set; }
    public Int64 PersonId { get; set; }
    public List<ViewPersonColumns> PersonColumns { get; set; } //not saved to session??

    public UserManagement() { }

    public UserManagement(DbContext dbContext, string userName)
    {
      var person = dbContext.Person.Single(p => p.UserName == userName);

      PersonUserName = person.UserName;
      PersonId = person.Id;
    }

    /*public void PrepareUserData(DbContext dbContext)
    {
      LoadPersonColumns(dbContext);
    }*/

    public void LoadPersonColumns(DbContext dbContext)
    {
      LoadPersonColumns(dbContext, null);
    }

    public void LoadPersonColumns(DbContext dbContext, string code)
    {
      PersonColumns = ViewPersonColumns.GetPersonColumns(dbContext, code, PersonId);
    }

    public List<ViewPersonColumns> GetFormViewColumns(Int64 formId, string viewName)
    {
      if (PersonColumns == null)
        return null;

      return PersonColumns.Where(p => p.FormId == formId && p.ObjectName == viewName).ToList();
    }

  }

将列保存到会话

UserManagement userManagement = new UserManagement(_context, user.UserName);
userManagement.LoadPersonColumns(_context);
HttpContext.Session.SetObject("ActualPersonContext", userManagement);
HttpContext.Session.SetObject("ActualPersonColumns", userManagement.PersonColumns);

从会话加载列

//userManagement build-in types are set. The PersonColumns is null - not correct
UserManagement userManagement = session.GetObject<UserManagement>("ActualPersonContext");
//The cols is filled from session with 600 records - correct
List<ViewPersonColumns> cols = session.GetObject<List<ViewPersonColumns>>("ActualPersonColumns");

Answer 1

每列使用列表比使用数据库更好。您不能像 .net framework 4.0 那样在 .net core 中创建和存储会话

试试这样

启动文件

 public void ConfigureServices(IServiceCollection services)
        {
            //services.AddDbContext<GeneralDBContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));        

            services.AddMvc().AddSessionStateTempDataProvider();
            services.AddSession();
        }

Common/SessionExtensions.cs

sing Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace IMAPApplication.Common
{
    public static class SessionExtensions
    {
        public static T GetComplexData<T>(this ISession session, string key)
        {
            var data = session.GetString(key);
            if (data == null)
            {
                return default(T);
            }
            return JsonConvert.DeserializeObject<T>(data);
        }

        public static void SetComplexData(this ISession session, string key, object value)
        {
            session.SetString(key, JsonConvert.SerializeObject(value));
        }
    }
}

用法

• ==> 创建会话*

public IActionResult Login([FromBody]LoginViewModel model)
        {               
          LoggedUserVM user = GetUserDataById(model.userId);   
          
          //Create Session with complex object   
          HttpContext.Session.SetComplexData("loggerUser", user);         
                
          return Json(new { status = result.Status, message = result.Message });              

        }

• ==> 获取会话数据*

 public IActionResult Index()
        {
            //Get Session data     
            LoggedUserVM loggedUser = HttpContext.Session.GetComplexData<LoggedUserVM>("loggerUser");                         
        }

希望这是有帮助的。祝你好运。