net core，当我在asp.net核心MVC单客户端身份验证中创建项目时，我得到了这个错误 .
处理请求时发生未处理的异常 .
SqlException： Build 与SQL Server的连接时发生与网络相关或特定于实例的错误 . 服务器未找到或无法访问 . 验证实例名称是否正确，以及SQL Server是否配置为允许远程连接 . （提供程序：SQL网络接口，错误：50 - 发生本地数据库运行时错误 . 无法创建自动实例 . 请参阅Windows应用程序事件日志以获取错误详细信息 . ）`System.Data.ProviderBase.DbConnectionPool.TryGetConnection（DbConnection owningObject，uint waitForMultipleObjectsTimeout ，bool allowCreate，bool onlyOneCheckConnection，DbConnectionOptions userOptions，out DbConnectionInternal connection）System.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft .EntityFrameworkCore.Storage.RelationalConnection d__31.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable AsyncEnumerator d__9.MoveNext（） System.Runtime.Exceptio nServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.EntityFrameworkCore.Storage.Internal.SqlServerExecutionStrategy d__6.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices .TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable AsyncEnumerator d__8.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.EntityFrameworkCore .Query.Internal.AsyncLinqOperatorProvider SelectAsyncEnumerable SelectAsyncEnumerator d _1.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvide r <_FirstOrDefault> d__82.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.EntityFrameworkCore.Query.Internal.TaskResultAsyncEnumerable Enumerator d__3.MoveNext（）System . Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider SelectAsyncEnumerable SelectAsyncEnumerator d__4.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System .Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider ExceptionInterceptor EnumeratorExceptionInterceptor d__5.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSucces sAndDebuggerNotification（任务任务）Microsoft.AspNetCore.Identity.UserValidator d__6.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.AspNetCore.Identity.UserValidator d__5 . MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.AspNetCore.Identity.UserManager d__157.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（） System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.AspNetCore.Identity.UserManager d__68.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft .AspNetCore.Identity.UserManager d__73.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）System.Runtime.CompilerServices.TaskAwaiter.GetResult（）
在AccountController.cs中
Testing_Sql_Web_Authentication.Controllers.AccountController d__10.MoveNext（）
public async Task<IActionResult> Register(RegisterViewModel model, string returnUrl = null)
{
ViewData["ReturnUrl"] = returnUrl;
if (ModelState.IsValid)
{
var user = new ApplicationUser { UserName = model.Email, Email = model.Email };
var result = await _userManager.CreateAsync(user, model.Password);
if (result.Succeeded)
{
// For more information on how to enable account confirmation and password reset please visit https://go.microsoft.com/fwlink/?LinkID=532713
// Send an email with this link
//var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
//var callbackUrl = Url.Action(nameof(ConfirmEmail), "Account", new { userId = user.Id, code = code }, protocol: HttpContext.Request.Scheme);
System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker d__27.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System .Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker d__25.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow（ActionExecutedContext context）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next（ref state next，ref Scope scope，ref object state，ref bool isCompleted）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker d__22.MoveNext（）System.Runtime.ExceptionServices . ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow（ResourceExecutedContext context）M icrosoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next（ref state next，ref Scope scope，ref object state，ref bool isCompleted）Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker d__20.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo . Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.AspNetCore.Builder.RouterMiddleware d__4.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task任务）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System . Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.AspNetCore.Authentication .AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification （任务任务）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（） System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Authentication.AuthenticationMiddleware d__18.MoveNext（）System . Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（） System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）Microsoft.VisualStudio.Web.BrowserLink.BrowserLinkMiddleware d__7.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task ）Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.MigrationsEndPointMiddleware d__5.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task task）Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware d__6 . MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware d__6.MoveNext（）System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw（）System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（Task任务）Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware d__7.MoveNext（）`