相关疑难解决方法(0)

我有一个在我的系统中完美运行的Web应用程序.但是,当我将其复制到另一个系统时,我无法登录该应用程序.有一个错误:

Server Error in '/' Application.
--------------------------------------------------------------------------------

Instance failure. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.InvalidOperationException: Instance failure.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Stack Trace: …

我的解决方案中有2个项目，有一个安装了Entity Framework Core的项目：

在另一个ASP.NET Web API项目中，我具有以下软件包：

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Antlr" version="3.5.0.2" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights" version="2.5.1" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights.Agent.Intercept" version="2.4.0" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights.DependencyCollector" version="2.5.1" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights.PerfCounterCollector" version="2.5.1" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights.Web" version="2.5.1" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights.WindowsServer" version="2.5.1" targetFramework="net461" />
  <package id="Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel" version="2.5.1" targetFramework="net461" />
  <package id="Microsoft.AspNet.Mvc" version="5.2.4" targetFramework="net461" />
  <package id="Microsoft.AspNet.Razor" version="3.2.4" targetFramework="net461" />
  <package id="Microsoft.AspNet.TelemetryCorrelation" version="1.0.0" targetFramework="net461" />
  <package id="Microsoft.AspNet.Web.Optimization" version="1.1.3" targetFramework="net461" />
  <package id="Microsoft.AspNet.WebApi" version="5.2.4" targetFramework="net461" />
  <package id="Microsoft.AspNet.WebApi.Client" version="5.2.4" targetFramework="net461" /> …

我有一个带有 AspNetCore.Identity Logins 的 ASP.NET Core Web 应用程序。它使用 SQL Server 进行用户身份验证。

我需要使用 PostgreSQL 数据库我添加了一些 nuget 包（EF.* 等），更改了连接字符串和代码

 public void ConfigureServices(IServiceCollection services)
        {
            services.Configure<CookiePolicyOptions>(options =>
            {
                // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                options.CheckConsentNeeded = context => true;
            });
//                options.UseSqlServer( Configuration.GetConnectionString("DefaultConnection")));
            services.AddDbContext<ApplicationDbContext>(options =>
                options.UseNpgsql( Configuration.GetConnectionString("DefaultConnection")));

            services.AddDefaultIdentity<IdentityUser>()
                .AddEntityFrameworkStores<ApplicationDbContext>();

            services.AddControllersWithViews()
                .AddNewtonsoftJson();
            services.AddRazorPages();
        }

但是当我运行它时，它连接到 PostgreSQL 数据库并尝试创建我收到错误的结构，有什么问题？为什么EF不能创建结构？如何解决这个问题呢？

  Executing endpoint 'WebApplication1.Controllers.HomeController.Index (WebA
pplication1)'
info: Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker[3]
      Route matched with {action = "Index", controller = "Home", page …

我正在使用 ASP.NET Core MVC 构建一个网站。我搭建了身份页面，并尝试将名字和姓氏属性添加到注册表中。我被困在根据表单输入设置用户名字/姓氏的位置上。下面是Register.cshtml.cs我搭建的文件。

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
#nullable disable

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Text.Encodings.Web;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.UI.Services;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.WebUtilities;
using Microsoft.Extensions.Logging;

namespace IssueTracker.Areas.Identity.Pages.Account
{
    public class RegisterModel : PageModel
    {
        private readonly SignInManager<IdentityUser> _signInManager;
        private readonly …