如何从jwt令牌登录用户并设置角色.net core 2.2

using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.IdentityModel.Tokens;

public void ConfigureServices(IServiceCollection services)
{
    // 添加身份验证服务
    services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
        .AddJwtBearer(options =>
        {
            options.TokenValidationParameters = new TokenValidationParameters
            {
                ValidateIssuer = true,
                ValidateAudience = true,
                ValidateLifetime = true,
                ValidateIssuerSigningKey = true,
                ValidIssuer = "your_issuer",
                ValidAudience = "your_audience",
                IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("your_secret_key"))
            };
        });

    // 其他配置...
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    // 启用身份验证中间件
    app.UseAuthentication();

    // 其他配置...
}

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.IdentityModel.Tokens;
using System;
using System.IdentityModel.Tokens.Jwt;
using System.Security.Claims;
using System.Text;

[Route("api/[controller]")]
[ApiController]
public class AuthController : ControllerBase
{
    private readonly IConfiguration _configuration;

    public AuthController(IConfiguration configuration)
    {
        _configuration = configuration;
    }

    [AllowAnonymous]
    [HttpPost("login")]
    public IActionResult Login(string username, string password)
    {
        // 在此处进行用户验证逻辑，验证成功后生成JWT令牌

        var claims = new[]
        {
            new Claim(ClaimTypes.Name, username),
            new Claim(ClaimTypes.Role, "admin") // 设置用户角色
        };

        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:SecretKey"]));
        var credentials = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

        var token = new JwtSecurityToken(
            _configuration["Jwt:Issuer"],
            _configuration["Jwt:Audience"],
            claims,
            expires: DateTime.Now.AddMinutes(30),
            signingCredentials: credentials
        );

        return Ok(new
        {
            token = new JwtSecurityTokenHandler().WriteToken(token)
        });
    }

    // 其他操作...
}

[Authorize(Roles = "admin")]
[HttpGet("admin")]
public IActionResult AdminAction()
{
    // 只有具有"admin"角色的用户才能访问此操作
    return Ok("Admin action executed.");
}