mvc 5 asp.net身份角色和用戶，如何避免同時使用戶具有其角色並刪除

Question

這里的系統就像一個用戶可能有很多角色，所以現在我可以列出用戶，但是我也想列出角色

該控制器將僅列出用戶，

public ActionResult listOfRolesForUser()
        {

            RoleManager<IdentityRole> RoleManager = new RoleManager<IdentityRole>(new RoleStore<IdentityRole>(ndb));
            UserManager<ApplicationUser> UserManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(ndb));
            ViewBag.AllUsers = UserManager.Users.ToList();
            return View();

        }

這是view或listOfRolesForUser.cshtml

@{
    ViewBag.Title = "listOfRolesForUser";
}

<h2>listOfRolesForUser</h2>
<table border="1">
    <tr>
        <td>User name</td>
        <td>Roles</td>
    </tr>
    @foreach (var item2 in ViewBag.AllUsers)
    {
        <tr>
            <td>@item2.UserName</td>
            <td>here i need to list related role too</td>
        </tr>
    }

</table>

現在我將如何像這樣列出：

Answer 1

要同時檢索“ 用戶”和“ 角色” ，您可以存儲兩個列表並傳遞給視圖模型。

public ActionResult Index()
{
    using (var context = new ApplicationDbContext())
    {
        UserManager<ApplicationUser> UserManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(context));

        var users = UserManager.Users;
        var roles = new List<string>();

        // retrieve roles for each user
        foreach (var user in users)
        {
            string str = "";
            foreach (var role in UserManager.GetRoles(user.Id))
            {
                str = (str == "") ? role.ToString() : str + " - " + role.ToString();
            }
            roles.Add(str);
        }

        var model = new HomeViewModel()
        {
            // create view model with these fields
            users = users.ToList(),
            roles = roles.ToList()
        };
        return View(model);
    }
}

使用視圖模型填充表，在HomeController實現Delete方法，並通過ajax調用導航到Home/Delete url。

@model WebApplication1.Models.HomeViewModel

<h2>listOfRolesForUser</h2>
<table border="1">
    <tr>
        <td>User name</td>
        <td>Roles</td>
        <td>Actions</td>
    </tr>

    @{
        int i = 0;

        foreach (var item in Model.users)
        {
            <tr id="@item.Id">
                <td>@item.UserName</td>
                <td>@Model.roles[i]</td>
                <td>
                    <a href="#" onclick="deleteUser('@item.Id')" id="btnDelete" data-toggle="modal" data-target="#deleteModal" title="Delete">
                        Delete
                    </a>
                </td>
            </tr>
            i++;
        }
    }
</table>