管理 ASP.NET Core 中的用户声明

涉及到的 Model 和 ViewModel：

namespace StudentManagement.Models
{
    public class UserClaim
    {
        public string ClaimType { get; set; }
        public bool IsSelected { get; set; }
    }
}
namespace StudentManagement.ViewModels
{
    public class UserClaimsViewModel
    {
        public string UserId { get; set; }
        public List<UserClaim> Claims { get; set; }
        public UserClaimsViewModel()
        {
            Claims = new List<UserClaim>();
        }
    }
}

为了方便调试，先制作一个内存中的 Claim 集合：

namespace StudentManagement.Models
{
    public class ClaimsStore
    {
        public static List<Claim> AllClaims = new List<Claim>
        {
            new Claim("Create Role","Create Role"),
            new Claim("Edit Role","Edit Role"),
            new Claim("Delete Role","Delete Role"),
            new Claim("Edit Student","Edit Student")
        };
    }
}

编辑用户声明的方法：

[HttpGet]
public async Task<IActionResult> ManageUserClaims(string userId)
{
    var user = await _userManager.FindByIdAsync(userId);
    if (user == null)
    {
        ViewBag.ErrorMessage = $"无法找到 Id {userId} 的用户";
        return View("NotFound");
    }
    // 获取用户当前所有 Claim
    var existingUserClaims = await _userManager.GetClaimsAsync(user);
    var model = new UserClaimsViewModel
    {
        UserId = userId
    };
    foreach (var claim in ClaimsStore.AllClaims)
    {
        var userClaim = new UserClaim
        {
            ClaimType = claim.Type
        };
        if (existingUserClaims.Any(c => c.Type == claim.Type))
        {
            userClaim.IsSelected = true;
        }
        model.Claims.Add(userClaim);
    }
    return View(model);
}
[HttpPost]
public async Task<IActionResult> ManageUserClaims(UserClaimsViewModel model)
{
    var user = await _userManager.FindByIdAsync(model.UserId);
    if (user == null)
    {
        ViewBag.ErrorMessage = $"无法找到 Id {model.UserId} 的用户";
        return View("NotFound");
    }
    var claims = await _userManager.GetClaimsAsync(user);
    var removeClaimsResult = await _userManager.RemoveClaimsAsync(user, claims);
    if (!removeClaimsResult.Succeeded)
    {
        ModelState.AddModelError("", "无法删除当前用户的声明");
        return View(model);
    }
    var addClaimsResult = await _userManager.AddClaimsAsync(user,
        model.Claims.Where(c => c.IsSelected).Select(c => new Claim(c.ClaimType, c.ClaimType)));
    if (!addClaimsResult.Succeeded)
    {
        ModelState.AddModelError("", "无法向用户添加选定的声明");
        return View(model);
    }
    return RedirectToAction("EditUser", new { Id = model.UserId });
}

管理用户声明的视图（和管理用户角色的视图很相似）：

@model UserClaimsViewModel
<form method="post">
    <div class="card">
        <div class="card-header">
            <h2>管理用户声明</h2>
        </div>
        <div class="card-body">
            @for (var i = 0; i < Model.Claims.Count; i++)
            {
                <div class="form-check m-1">
                    <input type="hidden" asp-for="@Model.Claims[i].ClaimType" />
                    <input asp-for="@Model.Claims[i].IsSelected" class="form-check-input" />
                    <label class="form-check-label" asp-for="@Model.Claims[i].IsSelected">
                        @Model.Claims[i].ClaimType
                    </label>
                </div>
            }
            <div asp-validation-summary="All" class="text-danger"></div>
        </div>
        <div class="card-footer">
            <input type="submit" value="更新" class="btn btn-primary" style="width: auto" />
            <a class="btn btn-primary" style="width: auto" asp-action="EditUser" asp-route-id="@Model.UserId">取消</a>
        </div>
    </div>
</form>