【C#

“/”应用程序中的服务器错误。Cannot drop database "MvcQlog" because it is currently in use.说明: 执行当前 Web 请求期间，出现未经处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。 异常详细信息: System.Data.SqlClient.SqlException: Cannot drop database "MvcQlog" because it is currently in use.源错误: 行 19:         public ActionResult Index()行 20:         {行 21:             return View(db.Qlogs.ToList());行 22:         }行 23: 源文件: e:\CSharp\EF\MvcQlog\MvcQlog\Controllers\HomeController.cs    行: 21 堆栈跟踪: [SqlException (0x80131904): Cannot drop database "MvcQlog" because it is currently in use.]   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +2442598   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5766516   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +285   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +4162   System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async, Int32 timeout, Boolean asyncWrite) +948   System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) +286   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +286   System.Data.SqlClient.<>c__DisplayClass39_0.<DropDatabase>b__0(SqlConnection conn) +34   System.Data.SqlClient.SqlProviderServices.UsingConnection(SqlConnection sqlConnection, Action`1 act) +92   System.Data.SqlClient.SqlProviderServices.UsingMasterConnection(SqlConnection sqlConnection, Action`1 act) +374   System.Data.SqlClient.SqlProviderServices.DropDatabase(SqlConnection sqlConnection, Nullable`1 commandTimeout, String databaseName) +96   System.Data.SqlClient.SqlProviderServices.DbDeleteDatabase(DbConnection connection, Nullable`1 commandTimeout, StoreItemCollection storeItemCollection) +231   System.Data.Objects.ObjectContext.DeleteDatabase() +83   System.Data.Entity.Internal.DatabaseOperations.DeleteIfExists(ObjectContext objectContext) +58   System.Data.Entity.Database.Delete() +137   System.Data.Entity.DropCreateDatabaseIfModelChanges`1.InitializeDatabase(TContext context) +283   System.Data.Entity.<>c__DisplayClass2`1.<SetInitializerInternal>b__0(DbContext c) +151   System.Data.Entity.Internal.<>c__DisplayClass8.<PerformDatabaseInitialization>b__6() +67   System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action) +110   System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization() +273   System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>b__4(InternalContext c) +31   System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input) +143   System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action) +270   System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase() +123   System.Data.Entity.Internal.InternalContext.Initialize() +42   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +39   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +137   System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator() +38   System.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator() +99   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +263   System.Linq.Enumerable.ToList(IEnumerable`1 source) +58   MvcQlog.Controllers.HomeController.Index() in e:\CSharp\EF\MvcQlog\MvcQlog\Controllers\HomeController.cs:21   lambda_method(Closure , ControllerBase , Object[] ) +101   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +19   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +209   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +28   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +15   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +49   System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +57   System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +223   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +15   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +49   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +24   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +44   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +15   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +54   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +44   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +12   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +44   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +11   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9765045   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155版本信息: Microsoft .NET Framework 版本:4.0.30319; ASP.NET 版本:4.6.1637.0

解决方法：

断开所有与数据库的连接或者停止数据库服务然后再重启（实在找不到哪里还在用就重启服务吧！）