Error handling
When an exception occurs in an ASP.NET Core web API application, the application will throw an exception. If this exception is not handled, the application will crash and cause a 500 error. The response body will contain the stack trace of the exception. Displaying the stack trace to the client is acceptable during development. However, we should never expose the stack trace to the client in production. The stack trace contains sensitive information about the application that can be used by attackers to attack the application.
Handling exceptions
Let’s look at an example. The MyWebApiDemo sample application has a controller named UsersController, which has an action to get a user by their user ID. This action looks as follows:
[HttpGet("{id:int}")]public ActionResult<User> Get(int id)
{
var user = Users.First(u => u.Id == id);
if (user == null)
{
...
