Why should you care?

Teams use Custom Validation Attributes when shipping admin panels, portals, and stores on ASP.NET Core MVC.

See it live — copy this example

Create an MVC project (dotnet new mvc), add the code, and run dotnet run.

// Custom Validation Attributes — ShopNest.Mvc example
public class HomeController : Controller
{
    public IActionResult Index() => View();
}

Run Example »

Edit the code and click Run — like W3Schools Try it Yourself.

What happened?

• Walk through the example top to bottom.
• Each line connects to Custom Validation Attributes.
• Change one piece, run dotnet run, and observe the result.

Try it yourself

1. Open the example for Custom Validation Attributes.
2. Type or paste it into ShopNest.Mvc in the right folder.
3. Run the app and verify behavior in the browser.
4. Change text or labels in the example and run again — watch the browser update.
5. Break the code on purpose (remove a semicolon), read the error message, then fix it.

Remember

Custom Validation Attributes — know what it does and when to use it. Practice on ShopNest before moving on. Use the Next lesson link when this feels comfortable.