Windows server is not listed under Network

Refer to this link: https://social.technet.microsoft.com/Forums/windows/en-US/6e133d2c-d0b8-48b0-8b32-94d6b010a224/server-does-not-appear-under-network?forum=w7itpronetworking

“Network discovery requires that the DNS Client, Function Discovery Resource Publication, SSDP Discovery, and UPnP Device Host services are started, you may check this on both sides to make sure they are started.”

Cannot restore database to SQL Server running in Docker container

I faced this issue, turned out when using docker cp to copy files to the container, the files were owned by root user and other users didn’t have read permission. This is because the files were copied from shared folder in Windows host to the linux VM.

Because only root can read, I couldn’t restore the DB using the copied file as the server cannot read the file.

Doing a chmod to add read permission before copying into the container solves the issue.

ApiController attribute magic

While working with ASP.NET Core, I find that the [ApiController] attribute does a lot of magic to my controller.

https://docs.microsoft.com/en-us/aspnet/core/web-api/?view=aspnetcore-3.1#apicontroller-attribute

It will automatically throws 400 bad request error back to the client, parse the service model from the request payload, and a bunch of other things.

I’m still not sure how model binding works without this attribute, maybe I would have to decorate the service with binding attributes for it to work.

ASP.NET Core Middleware not executed

When developing ASP.NET Core applications, if for some reason the breakpoints never hit when the browser tries to refresh or makes requests to the server.

One possible reason is that the responses are cached by the client, this is especially the case with static files. Use Ctrl-F5 in the browser to clear the cache. If the browser uses the data in the cache instead, there won’t be any requests to the server.

This of course applies to any other backend technologies, no requests, no breakpoint hits.

Use custom content-type header in WebAPI or MVC.

The content-type header of the response is affected by the accept header of the request. This is not very obvious at first.

So when you register a custom media type to the JsonFormatter or XmlFormatter, the content-type header will not be changed depending on the type of the response object. Rather it matches the accept header in the request.

If the accept header in the request is not accepted, then the services will default to application/json or application/xml.

Example: let’s say you have a service model called Student, a custom media type “application/mycompany.com+json”, and a web service endpoint that returns a student by ID.

If you just use the browser to make a request to this endpoint, the content-type header in the response will likely be set to “application/json” or “application/xml” depending on your preferred setting and browser.

However if you set the accept header in the request to “application/mycompany.com+json”, the content-type type response header will be set to the same type.

There is no mapping between the types and the service model from the backend side.

Sequence contains no element

When got this error using NHibernate, it’s likely that your mappings and data models are not registered with the NHibernate configuration object.

Simply add the Assembly that contains the mapping files and the model declaration and it will work.

Also, make sure the mapping files are configured to be embedded resource in the project.