c# - 无法将 [] 索引应用于 IConfiguration 类型的表达式

Question

我一直在尝试解决这个问题，但什么也想不起来了......
使用 token 的 Web 应用程序，但有些事情让我退缩。

var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_config["Tokens:Key"]));

这是整个代码:

 namespace DutchTreat.Controllers
{
    public class AccountController : Controller
    {
        private readonly ILogger<AccountController> _logger;
        private readonly SignInManager<StoreUser> _signInManager;
        private readonly UserManager<StoreUser> _userManager;
        private readonly IConfiguration _config;

        public AccountController(ILogger<AccountController> logger, SignInManager<StoreUser> signInManager, UserManager<StoreUser> userManager, IConfiguration config)
        {
            _logger = logger;
            _signInManager = signInManager;
            _userManager = userManager;
            _config = config;
        }
        public IActionResult Login()
        {
            if (this.User.Identity.IsAuthenticated)
            {
                return RedirectToAction("Index", "App");
            }
            return View();
        }
        [HttpPost]
        public async Task<IActionResult> Login(LoginViewModel model)
        {
            if (ModelState.IsValid)
            {
                var result = await _signInManager.PasswordSignInAsync(model.UserName, model.Password, model.RememberMe, false);
                if (result.Succeeded)
                {
                    if (Request.Query.Keys.Contains("ReturnUrl"))
                    {
                        return Redirect(Request.Query["ReturnUrl"].First());
                    }
                    else
                    {
                        return RedirectToAction("Shop", "App");
                    }
                }
            }

            ModelState.AddModelError("", "Failed to login");

            return View();
        }

        [HttpGet]
        public async Task<IActionResult> Logout()
        {
            await _signInManager.SignOutAsync();
            return RedirectToAction("Index", "App");
        }

        [HttpPost]
        public async Task<IActionResult> CreateToken([FromBody] LoginViewModel model)
        {
            if (ModelState.IsValid)
            {
                var user = await _userManager.FindByNameAsync(model.UserName);
                if (user != null)
                {
                    var result = await _signInManager.CheckPasswordSignInAsync(user, model.Password, false);
                    if (result.Succeeded)
                    {
                        //Create the token
                        var claims = new[]
                        {
                            new Claim(JwtRegisteredClaimNames.Sub, user.Email),
                            new Claim(JwtRegisteredClaimNames.Jti, new Guid().ToString()),
                        };

                        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_config["Tokens:Key"]));
                    }
                }

            }

            return BadRequest();
        }
    }
}

Answer 1

如果这是 .NET Core，则有 GetValue<T>()函数，或 GetValue()如果要默认为字符串，则使用函数。

我使用它，因为我遇到了同样的错误。

引用这里 MSDN

但是在您的情况下它的基本用法是:
_config.GetValue<string>("Token:Key")
或者
_config.GetValue("Token:Key")