电子邮件令牌确认

最核心的一句代码：
var token = await _userManager.GenerateEmailConfirmationTokenAsync(user);

生成的确认链接：
http://localhost:3290/Account/ConfirmEmail?userId=ee5d09fb…&token=CfDJ8OM7Qj…

在 Startup 中修改 Identity 配置：

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddIdentity<ApplicationUser, IdentityRole>()
        .AddErrorDescriber<CustomIdentityErrorDescriptor>()
        .AddEntityFrameworkStores<AppDbContext>()
        .AddDefaultTokenProviders();
    ...
}

AdminController 中添加确认邮箱：

[HttpGet]
public async Task<IActionResult> ConfirmEmail(string userId, string token)
{
    if (userId == null || token == null)
    {
        return RedirectToAction("index", "home");
    }
    var user = await _userManager.FindByIdAsync(userId);
    if (user == null)
    {
        ViewBag.ErrorMessage = $"当前{userId}无效";
        return View("NotFound");
    }
    var result = await _userManager.ConfirmEmailAsync(user, token);
    if (result.Succeeded)
    {
        return View();
    }
    ViewBag.ErrorTitle = "您的电子邮箱尚未进行验证。";
    return View("Error");
}

ConfirmEmail 对应的视图：

<h3>您的电子邮件已经验证成功</h3>
<a asp-controller="Home" asp-action="Index">返回首页</a>

注册时检查邮箱是否已验证：

[HttpPost]
public async Task<IActionResult> Register(RegisterViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = new ApplicationUser
        {
            UserName = model.Email,
            Email = model.Email,
            City = model.City
        };
        var result = await _userManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
        {
            // 生成电子邮件确认令牌
            var token = await _userManager.GenerateEmailConfirmationTokenAsync(user);
            // 生成电子邮件的确认链接
            var confirmationLink = Url.Action("ConfirmEmail", "Account",
                new { userId = user.Id, token = token }, Request.Scheme);
            _logger.Log(LogLevel.Warning, confirmationLink);
            if (_signInManager.IsSignedIn(User) && User.IsInRole("Admin"))
            {
                return RedirectToAction("ListUsers", "Admin");
            }
            ViewBag.ErrorTitle = "注册成功";
            ViewBag.ErrorMessage = "在你登入系统前,我们已经给您发了一份邮件，需要您先进行邮件验证，点击确认链接即可完成。";
            return View("Error");
        }
        foreach (var error in result.Errors)
        {
            ModelState.AddModelError(string.Empty, error.Description);
        }
    }
    return View(model);
}