Validating the Model

Explore how to validate models in ASP.NET Core MVC by applying validation attributes, managing model state errors, and showing error messages in views. Understand how to enhance form data integrity using range, required, and regular expression validations within your website built on the MVC pattern. Practice handling HTTP POST requests and updating views to reflect validation feedback for improved user experience.

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Applying validation rules on model state
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The model binding process can cause errors, for example, data type conversions or validation errors, if the model has been decorated with validation rules. What data has been bound, and any binding or validation errors are stored in ControllerBase.ModelState.

Applying validation rules on model state

Let’s explore what we can do with the model state by applying some validation rules to the bound model and then showing invalid data messages in the view:

Step 1: In the Models folder, open Thing.cs.

Step 2: Import the namespace for working with validation attributes, as shown ...

1.Introduction

2.Hello, C#! Welcome, .NET!

3.Speaking C#

4.Controlling Flow, Converting Types, and Handling Exception

5.Writing, Debugging, and Testing Functions

6.Building Your Own Types with Object-Oriented Programming

7.Implementing Interfaces and Inheriting Classes

8.Packaging and Distributing .NET Types

9.Working with Common .NET Types

10.Working with Files, Streams, and Serialization

11.Working with Data Using Entity Framework Core

12.Querying and Manipulating Data Using LINQ

13.Introducing Web Development Using ASP.NET Core

14.Building Websites Using ASP.NET Core Razor Pages

15.Building Websites Using the Model-View-Controller Pattern

16.Building and Consuming Web Services

17.Building User Interfaces Using Blazor

18.Conclusion

Validating the Model

Applying validation rules on model state