ASP.NET Core Interview Question #90

What is exception handling middleware in ASP.NET Core?

Middleware & Request Pipeline Mid-Level Intermediate

Quick Interview Answer

Exception handling middleware catches unhandled exceptions thrown by downstream components and converts them into an appropriate response.

Detailed Explanation

Exception handling middleware catches unhandled exceptions thrown by downstream components and converts them into an appropriate response.

In production MVC applications, UseExceptionHandler() can redirect or re-execute a safe error endpoint without exposing sensitive exception details. APIs can use centralized exception handling to produce consistent error responses.

The middleware should be placed early enough in the pipeline to catch exceptions from the components that follow it.

Code Example

if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
}
else
{
    app.UseExceptionHandler("/Home/Error");
}