Error: The type or namespace UI does not exist in the namespace Microsoft.AspNetCore.Identity bootstrap dotnet core 3.0

Error: The type or namespace UI does not exist in the namespace Microsoft.AspNetCore.Identity bootstrap dotnet core 3.0

Title
Understanding and Implementing Identity with ASP.NET Core 3.0
A Deep Dive into Microsoft's Authentication Framework

ASP.NET Core is an open-source, cross-platform framework for building modern web applications. One of its most powerful features is Identity, an authentication and authorization framework that simplifies the process of adding user sign-in functionality to your applications. In this blog post, we'll explore the basics of Identity in ASP.NET Core 3.0, including its architecture, key components, and implementation steps.

**What is Identity in ASP.NET Core?**

Microsoft Identity is an authentication framework that provides built-in support for individual user sign-in, password storage, and other security features. It's designed to work seamlessly with ASP.NET Core applications, allowing developers to focus on building their applications rather than managing authentication and authorization details.

**Architecture of Identity in ASP.NET Core**

At its core, Identity consists of three main components

1. **Identity Framework**
This is the core library that provides the building blocks for authentication and authorization. It includes classes for managing users, roles, claims, and middleware components for handling authentication requests.

2. **Identity Data Store**
This is where user data is stored, such as usernames, passwords, and email addresses. In ASP.NET Core, Identity supports several data stores, including SQL Server, SQLite, and In-Memory.

3. **Identity UI**
This is an optional component that provides pre-built UI components for sign-in, registration, and password reset pages. It's built using Razor Pages and can be easily integrated into your application.

**Setting up Identity in ASP.NET Core**

To get started with Identity in ASP.NET Core, follow these steps

**Step 1
Create a new project**

First, create a new ASP.NET Core Web Application using Visual Studio or the .NET CLI

sh
dotnet new webapp -o MyApp

**Step 2
Add Identity**

Next, add Identity to your project by installing the `Microsoft.AspNetCore.Identity.Stores` and `Microsoft.AspNetCore.Identity.UI` NuGet packages

sh
dotnet add package Microsoft.AspNetCore.Identity.Stores
dotnet add package Microsoft.AspNetCore.Identity.UI

**Step 3
Configure Identity**

Open the `appsettings.json` file and add the following configuration

json
{
  "ConnectionStrings"
 {
    "DefaultConnection"
 "Server=(localdb)\\mssqllocaldb;Database=aspnet-MyApp-Identity;Trusted_Connection=True;MultipleActiveResultSets=true"
  },
  "Logging"
 {
    "LogLevel"
 {
      "Default"
 "Information",
      "Microsoft"
 "Warning",
      "Microsoft.Hosting.Lifetime"
 "Information"
    }
  },
  "AllowedHosts"
 "*"
}

Replace the `DefaultConnection` value with your own SQL Server connection string.

Next, open the `Program.cs` file and add the following lines at the end

csharp

using Microsoft.EntityFrameworkCore;

using Microsoft.Extensions.DependencyInjection;

using Microsoft.Extensions.Hosting;

using MyApp.Data;

using Microsoft.AspNetCore.Identity;

using Microsoft.AspNetCore.Identity.UI;

using Microsoft.AspNetCore.Identity.Stores;

public static IHostBuilder CreateHostBuilder(string[] args) =>

Host.CreateDefaultBuilder(args)

.ConfigureWebHostDefaults(webBuilder =>

{

webBuilder.UseStartup();

webBuilder.UseDatabaseContext();

webBuilder.UseIdentity(options =>

{

options.Password.RequireDigit = true;

options.Password.RequireLowercase = true;

options.Password.RequireUppercase = true;

options.Password.RequireNonAlphanumeric = true;

options.Password.RequiredLength = 6;

});

webBuilder.UseIdentityServer();

webBuilder.UseAuthentication();

webBuilder.UseAuthorization();

webBuilder.UseEndpoints(endpoints =>

{

end