ASP.NET MVC 5页面挂起db调用

Question

我正在尝试使用ASP.NET Identity 2.0启动并运行MVC 5项目.我的出发点是本教程中的示例应用程序.我的初始页面是Home/Index.当我尝试进行搜索(期望返回值为null)时,应用程序只会挂起,我无法弄清楚原因.db上下文的实例化导致调用Seed()方法,这似乎正常,但它挂起在roleManager.FindByName(roleName)调用上(我在下面的代码中对它进行了评论).暂停调试器显示它被卡住但我不知道从那里去哪里.相关课程如下.

控制器:

public class HomeController : ApplicationController
{         
    public ActionResult Index()
    {
        var user = db.Users.Find("dummyVal");

        return View();
    }

    [Authorize]
    public ActionResult About()
    {
        ViewBag.Message = "Your app description page.";

        return View();
    }

    public ActionResult Contact()
    {
        ViewBag.Message = "Your contact page.";

        return View();
    }
}

基础控制器:

public abstract class ApplicationController : Controller
{
    protected ApplicationDbContext db;

    public ApplicationController()
    {
        db = new ApplicationDbContext();
    }
}

DB初始化器:

public class ApplicationDbInitializer : DropCreateDatabaseAlways<ApplicationDbContext> 
{
    protected override void Seed(ApplicationDbContext context) {
        InitializeIdentityForEF(context);
        base.Seed(context);
    }

    //Create User=Admin@Admin.com with password=Admin@123456 in the Admin role        
    public static void InitializeIdentityForEF(ApplicationDbContext db) {
        var userManager = HttpContext.Current.GetOwinContext().GetUserManager<ApplicationUserManager>();
        var roleManager = HttpContext.Current.GetOwinContext().Get<ApplicationRoleManager>();
        const string name = "admin@example.com";
        const string password = "Admin@123456";
        const string roleName = "Admin";

        //Create Role Admin if it does not exist
        // EXECUTION HANGS ON THIS CALL...
        var role = roleManager.FindByName(roleName);
        if (role == null) {
            role = new IdentityRole(roleName);
            var roleresult = roleManager.Create(role);
        }

        var user = userManager.FindByName(name);
        if (user == null) {
            user = new ApplicationUser { UserName = name, Email = name };
            var result = userManager.Create(user, password);
            result = userManager.SetLockoutEnabled(user.Id, false);
        }

        // Add user admin to Role Admin if not already added
        var rolesForUser = userManager.GetRoles(user.Id);
        if (!rolesForUser.Contains(role.Name)) {
            var result = userManager.AddToRole(user.Id, role.Name);
        }

        // Create dummy user
        const string dummyUserName = "PeterVenkman";
        const string dummyUserPwd = "gf%^^ftf83X";

        var dummyUser = userManager.FindByName(dummyUserName);
        if (dummyUser == null) { 
            dummyUser = new ApplicationUser { UserName = dummyUserName, Email = dummyUserName };
            var result = userManager.Create(dummyUser, dummyUserPwd);
            result = userManager.SetLockoutEnabled(dummyUser.Id, false);
        }
    }
}

Answer 1

该错误是因为您在控制器中实例化dbContext对象而不是从owin上下文中获取它.控制器中存在两个不同的上下文对象,而同一个数据库中的启动中存在一个上下文对象导致此死锁.解决此问题的最简单方法是替换代码

            db = new ApplicationDbContext();

同

db = System.Web.HttpContext.Current.GetOwinContext().Get<ApplicationDbContext>();

解决了这个问题