我无法使用角色管理器删除用户角色

Question

我尝试通过 UI 上的复选框为用户删除或添加角色，但出现了一些错误

await _userManager.IsInRoleAsync(user, roleName)

此代码总是返回 false，我无法检查。

var user = await _userManager.FindByIdAsync(id.ToString());
var roles = await _userManager.GetRolesAsync(user);

我仍然可以得到roles 的user。 谁能解释我收到此错误的原因？

private readonly UserManager<User> _userManager;
private readonly SignInManager<User> _signInManager;
private readonly RoleManager<Role> _roleManager;
private readonly IConfiguration _config;
private readonly IMapper _mapper;

public UserService(UserManager<User> userManager, 
    SignInManager<User> signInManager, RoleManager<Role> roleManager,
    IConfiguration config,
    IMapper mapper)
{
    _signInManager = signInManager;
    _userManager = userManager;
    _roleManager = roleManager;
    _config = config;
    _mapper = mapper;
}    
public async Task<ApiResult<bool>> RoleAssign(int id, RoleAssignRequest request)
{
    var user = await _userManager.FindByIdAsync(id.ToString());
    var roles = await _userManager.GetRolesAsync(user);
    var listRole = await _roleManager.RoleExistsAsync("admin");
    if (user == null)
    {
        return new ApiErrorResult<bool>("Tài khoản không tồn tại");
    }
    var removedRoles = request.Roles.Where(x => x.Selected == false).Select(x => x.Name).ToList();
    foreach (var roleName in removedRoles)
    {
        if (await _userManager.IsInRoleAsync(user, roleName) == true)
        {
            await _userManager.RemoveFromRoleAsync(user, roleName);
        }
    }
    await _userManager.RemoveFromRolesAsync(user, roles);
    
    var addedRoles = request.Roles.Where(x => x.Selected).Select(x => x.Name).ToList();
    foreach (var roleName in addedRoles)
    {
        if (await _userManager.IsInRoleAsync(user, roleName) == false)
        {
            await _userManager.AddToRoleAsync(user, roleName);
        }
    }
    
    return new ApiSuccessResult<bool>();
}

Answer 1

当您尝试删除用户角色时：您可以这样做，我希望它会起作用。 它只是一个基本的例子。 删除角色代码：

 ApplicationUser user = UserManager.FindById(UserId.ToString());
            if (user != null)
            {
                foreach (var r  in user.Roles.ToList())
                {
                    user.Roles.Remove(r);
                }
            }

添加角色代码::

  IdentityUserRole userrole = new IdentityUserRole();
                           //add user information in userrole according to your buisness logic
                            user.Roles.Add(userrole);

Answer 2

查看UserManager.RemoveFromRoleAsync(TUser, String) 方法的源码可以发现，如果用户不在指定的角色中，会返回UserNotInRoleError。

public virtual async Task<IdentityResult> RemoveFromRoleAsync(TUser user, string role)
{
    ThrowIfDisposed();
    var userRoleStore = GetUserRoleStore();
    if (user == null)
    {
        throw new ArgumentNullException(nameof(user));
    }

    var normalizedRole = NormalizeName(role);
    if (!await userRoleStore.IsInRoleAsync(user, normalizedRole, CancellationToken))
    {
        return UserNotInRoleError(role);
    }
    await userRoleStore.RemoveFromRoleAsync(user, normalizedRole, CancellationToken);
    return await UpdateUserAsync(user);
}

要为指定用户添加/删除角色，您可以在添加/删除操作之前尝试检查角色是否存在并检查用户是否已经在角色中，如下所示。

将指定用户添加到命名角色

//add user to the named role

bool role_is_existing = await _roleManager.RoleExistsAsync(roleName);

//if the specified role name is not existing
//create the the specified role
if (!role_is_existing)
{
    var role = new IdentityRole();
    role.Name = roleName;
    await _roleManager.CreateAsync(role);
}

//check if the current user is a member of the given named role
var isInRole = await _userManager.IsInRoleAsync(user, roleName);

if (!isInRole)
{
    //add to role
    await _userManager.AddToRoleAsync(user, roleName);
}

从命名角色中删除指定用户

//check if the current user is a memeber of the given named role
var isInRole = await _userManager.IsInRoleAsync(user, roleName);

if (isInRole)
{
    await _userManager.RemoveFromRoleAsync(user, roleName);
}

当我从用户那里删除角色时，它会通知 UserNotInRole

请确保AspNetRoles表中的实际数据，并检查映射当前用户和指定角色的记录是否存储在AspNetUserRoles表中。