我正在Visual Studio 2012 Express中开发代码优先的Web应用程序。
我在web.config中使用以下连接字符串:
<add name="myContext" connectionString="Data Source=.;Integrated Security=True;Initial Catalog=cityKingMVC4" providerName="System.Data.SqlClient" />
我正在使用SimpleMembership。
我正在尝试从Filters/InitializeSimpleMembershipAttribute.cs播种1个管理员:
...
WebSecurity.InitializeDatabaseConnection("myContext", "Users", "UserId", "Email", autoCreateTables: true);
// A: Create Admin user
if (!WebSecurity.ConfirmAccount("[email protected]"))
{
WebSecurity.CreateUserAndAccount("[email protected]", "password");
}
// B: Create admin role if not exist
if (!Roles.RoleExists("Administrator"))
{
Roles.CreateRole("Administrator");
Roles.AddUserToRole("[email protected]", "Administrator");
}
如果我评论A和B，它不会崩溃。如果我不明白这一点:
“WebSecurity.InitializeDatabaseConnection”方法只能调用一次。
如果我调试并将断点放在“WebSecurity.InitializeDatabaseConnection”上，则它将仅调用一次，并且没有其他代码在任何地方调用WebSecurity.InitializeDatabaseConnection。
如果我调试-它在文件(标准SimpleAuthentication文件)中更高的另一行崩溃:
LazyInitializer.EnsureInitialized(ref _initializer，ref _isInitialized，ref _initializerLock);
出现此错误:
调用的目标已引发异常。
堆栈跟踪:
[InvalidOperationException: The "WebSecurity.InitializeDatabaseConnection" method can be called only once.]
WebMatrix.WebData.WebSecurity.InitializeMembershipProvider(SimpleMembershipProvider simpleMembership, DatabaseConnectionInfo connect, String userTableName, String userIdColumn, String userNameColumn, Boolean createTables) +87978
WebMatrix.WebData.WebSecurity.InitializeProviders(DatabaseConnectionInfo connect, String userTableName, String userIdColumn, String userNameColumn, Boolean autoCreateTables) +86
myapPMVC4.Filters.SimpleMembershipInitializer..ctor() in c:\Users\name\Documents\Visual Studio 2012\Projects\myapPMVC4\myapPMVC4\Filters\InitializeSimpleMembershipAttribute.cs:43
[InvalidOperationException: The ASP.NET Simple Membership database could not be initialized. For more information, please see http://go.microsoft.com/fwlink/?LinkId=256588]
myapPMVC4.Filters.SimpleMembershipInitializer..ctor() in c:\Users\name\Documents\Visual Studio 2012\Projects\myapPMVC4\myapPMVC4\Filters\InitializeSimpleMembershipAttribute.cs:88
[TargetInvocationException: Exception has been thrown by the target of an invocation.]
System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0
System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +159
System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +256
System.Activator.CreateInstance(Type type, Boolean nonPublic) +127
System.Activator.CreateInstance(Type type) +11
System.Threading.LazyHelpers`1.ActivatorFactorySelector() +72
System.Threading.LazyInitializer.EnsureInitializedCore(T& target, Boolean& initialized, Object& syncLock, Func`1 valueFactory) +241
System.Threading.LazyInitializer.EnsureInitialized(T& target, Boolean& initialized, Object& syncLock) +139
myapPMVC4.Filters.InitializeSimpleMembershipAttribute.OnActionExecuting(ActionExecutingContext filterContext) in c:\Users\name\Documents\Visual Studio 2012\Projects\myapPMVC4\myapPMVC4\Filters\InitializeSimpleMembershipAttribute.cs:22
System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeActionMethodFilterAsynchronously(IActionFilter filter, ActionExecutingContext preContext, Func`1 nextInChain) +145
System.Web.Mvc.Async.AsyncControllerActionInvoker.InvokeActionMethodFilterAsynchronously(IActionFilter filter, ActionExecutingContext preContext, Func`1 nextInChain) +840201
System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__31(AsyncCallback asyncCallback, Object asyncState) +266
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +146
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag, Int32 timeout) +202
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag) +112
System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__1e(AsyncCallback asyncCallback, Object asyncState) +839055
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +146
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag, Int32 timeout) +166
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag) +27
System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__17(AsyncCallback asyncCallback, Object asyncState) +50
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +146
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag, Int32 timeout) +166
System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +826145
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +146
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag, Int32 timeout) +166
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate endDelegate, Object tag) +27
System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +401
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__2(AsyncCallback asyncCallback, Object asyncState) +786250
System.Web.Mvc.Async.WrappedAsyncResult`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +146
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate`1 endDelegate, Object tag, Int32 timeout) +166
System.Web.Mvc.Async.AsyncResultWrapper.Begin(AsyncCallback callback, Object state, BeginInvokeDelegate beginDelegate, EndInvokeDelegate endDelegate, Object tag) +27
System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +343
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +12550291
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288
这是怎么回事？
谢谢
using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Threading;
using System.Web.Mvc;
using WebMatrix.WebData;
using System.Web.Security;
using myapPMVC4.Models;
namespace myapPMVC4.Filters
{
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public sealed class InitializeSimpleMembershipAttribute : ActionFilterAttribute
{
private static SimpleMembershipInitializer _initializer;
private static object _initializerLock = new object();
private static bool _isInitialized;
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
LazyInitializer.EnsureInitialized(ref _initializer, ref _isInitialized, ref _initializerLock);
}
private class SimpleMembershipInitializer
{
public SimpleMembershipInitializer()
{
Database.SetInitializer<UsersContext>(null);
try
{
using (var context = new UsersContext())
{
if (!context.Database.Exists())
{
// Create the SimpleMembership database without Entity Framework migration schema
((IObjectContextAdapter)context).ObjectContext.CreateDatabase();
}
}
//WebSecurity.InitializeDatabaseConnection("DefaultConnection", "UserProfile", "UserId", "UserName", autoCreateTables: true);
if (!WebSecurity.Initialized)
{
WebSecurity.InitializeDatabaseConnection("myapPMVC4DBContext", "Users", "UserId", "Email", autoCreateTables: true);
}
// Create Admin user
if (!WebSecurity.ConfirmAccount("[email protected]"))
{
//WebSecurity.CreateUserAndAccount("admin", "pass", new { email = "[email protected]" });
WebSecurity.CreateUserAndAccount("[email protected]", "pass");
}
// Create admin role if not exist
if (!Roles.RoleExists("Administrator"))
{
Roles.CreateRole("Administrator");
Roles.AddUserToRole("[email protected]", "Administrator");
}
}
catch (Exception ex)
{
throw new InvalidOperationException("The ASP.NET Simple Membership database could not be initialized. For more information, please see http://go.microsoft.com/fwlink/?LinkId=256588", ex);
}
}
}
}
}
最佳答案
问题 ...
是InitializeDatabaseConnection在内部调用WebSecurity.InitializeProviders，而此方法不是线程安全的，然后将此与WebSecurity通常需要在各个地方进行初始化的事实结合起来。这具有影响，因为Web应用程序本质上是多线程环境...并且WebSecurity.Initialized和WebSecurity.InitializeDatabaseConnection一起使用时不是线程安全的-它们创建了典型的竞争条件。
播种(用于迁移)意味着您的WebSecurity可以被初始化一次以上，因为您可能还需要在Global.asax.cs中将其初始化以关闭播种的部署，并且您的InitializeSimpleMembershipAttribute可能会被HTTP请求同时调用多次。实时部署等
将初始化代码放在多个位置也会破坏DRYness
解决方案 ...
确保您的init调用是线程安全的，并且每个AppDomain实例仅发生一次。使用线程安全的单例类来执行此操作；并减少代码重复。
根据您的应用程序，从以下任何/全部中调用单例的EnsureInitialize方法:
Application_Start方法)Seed方法(在创建用户之前)SimpleMembershipInitializer构造函数中)这是一个简单的单例示例:
// Call this with WebSecurityInitializer.Instance.EnsureInitialize()
public class WebSecurityInitializer {
private WebSecurityInitializer() { }
public static readonly WebSecurityInitializer Instance = new WebSecurityInitializer();
private bool isNotInit = true;
private readonly object SyncRoot = new object();
public void EnsureInitialize() {
if (isNotInit) {
lock (this.SyncRoot) {
if (isNotInit) {
isNotInit = false;
WebSecurity.InitializeDatabaseConnection("MyContextName",
userTableName: "UserProfile", userIdColumn: "UserId", userNameColumn: "UserName",
autoCreateTables: true);
}
}
}
}
}
脚注
singleton类还保留您的代码DRY，这在早期应用程序开发中特别有用，如果您以后需要更改
WebSecurity.InitializeDatabaseConnection的配置，因为它只会放在一个位置(结束编辑)我还保持
SimpleMembershipInitializer整洁，并为我的用户和Migrations\Configuration.cs Seed方法中的常见种子设定种子。通过将所有内容都放在一个位置，这有助于通过我的迁移进行播种的可测试性。我使用单元测试来确保我们始终可以在迁移树上上下移动，因此这样做更容易。但是，您的种子代码的位置无关紧要，它只是确保在全局范围内仅在AppDomain中初始化WebSecurity一次，并且对
InitializeDatabaseConnection的任何调用都是线程安全的。关于ASP.NET MVC 4， "WebSecurity.InitializeDatabaseConnection"方法只能被调用一次，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/16508934/