英文:
ASP.NET Core Identity redirection breaks when using postgres?
问题
我有一个小的Blazor Server应用程序，通过EntityFramework 7运行Asp.net Core Identity。我之前一直在使用SQL Server，直到今天我尝试切换托管提供程序。当我尝试使用Entity Framework的NpgSql数据连接器来执行完全相同的操作时，应用程序表现得非常奇怪。当我登录时，结果是成功的，但然后从MVC重定向回Blazor应用程序时超时。如果我然后刷新页面，我仍然在登录页面上，但现在已经登录，可以正常使用应用程序。这可能是我的问题是什么？
我想分享更多的代码，但唯一的区别是从以下内容切换：
builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer("<string>"));
到
builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseNpgsql("<string>"));
我的第一个想法是EfCore的某些部分仍然试图使用SQL Server数据提供程序，但为什么刷新后我能正确登录呢？
编辑：刚刚发现另一个症状-显然，所有Blazor功能（状态更改，从方法重定向）现在都无法正常工作。就像Blazor的server.js文件没有被加载一样-但它确实被正确加载，没有JS错误发生。感觉自己快要发疯了。
英文:
I've got a small Blazor Server app running with Asp.net Core Identity through EntityFramework 7. I had been using a SQL server, until today when I tried to switch hosting providers. When I try to do the exact same thing with the NpgSql data connector for Entity Framework, the application behaves very strangely. When I log in, the result is a success, but then the redirect from MVC back to the Blazor app times out. If I then refresh the page, I'm still on the Login page, but now signed in, and can use the application as normal. What could be my issue here?
I would share more of my code, but the only difference is going from
builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer("<string>"));
to
builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseNpgsql("<string>"));
My first thought was that there's some part of EfCore that's still trying to use Sql server data providers, but then why would I be correctly signed in on refresh?
EDIT: Just discovered another symptom- apparently, all blazor functions (state change, redirects from methods) are now nonfunctional. It's like if the blazor.server.js file isn't being loaded- but it is being loaded correctly, and no JS errors are happening. Feel like I'm going crazy here.
答案1
得分: 0
事实证明，我在程序的其他地方存在线程问题。我在这里使用了这段代码
currentUser = UserManager.FindByNameAsync(authState.User.Identity.Name).Result;
我在这里使用了.Result()而不是等待该方法，以为这会同步运行-我现在意识到这是不良实践，因为以这种方式使用.Result()会导致死锁。不知何故，当我使用Entity Framework的SQL Server数据提供程序时，这段代码是正常的-我猜测SQL Server的冷启动时间可能比我现在使用的Postgres服务器快了一点，因此该方法需要更长的时间-然后陷入了死锁。
我重构了代码以正确等待该方法，现在一切都正常工作。
英文:
EDIT
Turns out I was having a threading issue elsewhere in my program. I was using this code
currentUser = UserManager.FindByNameAsync(authState.User.Identity.Name).Result;
I had used .Result() here instead of awaiting the method in thinking this would run synchronously- I now realize this is bad practice, as using .Result() in this way is a deadlock waiting to happen. Somehow, this code was fine when using the SQL Server data provider for Entity Framework- My guess is that the cold start time for the SQL server was a bit faster than the Postgres server I'm now using, and because of this the method was taking a fraction of a second longer- then running into a deadlock.
I refactored the code to properly await the method, and now everything works perfectly.
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