Implement the JsonSerializer class in C# apps

5 minutes

The C# programming language provides built-in support for working with JSON data through the System.Text.Json namespace. This namespace includes classes and methods for serializing and deserializing JSON data, making it easy to convert C# objects to JSON and vice versa.

What is serialization?

Serialization is the process of converting the state of an object (the values of its properties) into a form that can be stored or transmitted. The serialized form doesn't include any information about an object's associated methods.

In the context of a C# application, serialization is used to convert a C# object into a JSON string. This is useful for saving data to files, sending data over networks, or storing data in databases. For example:

Serialization is essential for data interchange between different systems or applications, especially when they use different programming languages or platforms. It allows for easy sharing of data in a standardized format that can be understood by various systems.
Serialization is also used in web APIs to send and receive data between clients and servers. When a client makes a request to a server, the server can serialize the response data into JSON format, which the client can then deserialize back into an object.
Serialization is used in data storage scenarios, such as saving application state or user preferences. By serializing objects to JSON, developers can easily store and retrieve complex data structures without needing to manually parse or format the data.
Serialization is often used in caching mechanisms, where data is stored in a serialized format to improve performance and reduce the need for repeated database queries or computations.

Deserialization is the reverse process of serialization, where a JSON string is converted back into a C# object. Deserialization allows developers to work with JSON data in a more structured way, using C# objects and properties. This is particularly useful when working with APIs or external data sources that return JSON responses, or when working with information stored in JSON files.

Examine the `System.Text.Json` namespace

The System.Text.Json namespace is a powerful library in .NET for working with JSON data. It provides functionality for both serialization (converting C# objects to JSON) and deserialization (converting JSON back to C# objects). The library is designed to be fast, efficient, and easy to use, making it a popular choice for developers working with JSON in C# applications.

The System.Text.Json library is part of the .NET Core framework and is included in .NET 5 and later versions. It provides a set of classes and methods for working with JSON data, including:

JsonSerializer: A class for converting C# objects to JSON and vice versa. It provides methods for serializing and deserializing JSON data, as well as options for customizing the serialization process.
JsonDocument: A class for reading and parsing JSON data. It allows developers to navigate and query JSON structures without needing to deserialize them into C# objects.
JsonElement: A struct that represents a JSON value. It provides methods for accessing and manipulating JSON data, allowing developers to work with JSON structures in a more flexible way.

The JsonSerializer class is the primary class used for serialization and deserialization in the System.Text.Json namespace. It provides methods for converting C# objects to JSON strings and vice versa, making it easy to work with JSON data in C# applications.

Examine the `JsonSerializer` class

The JsonSerializer class provides the following methods for serializing and deserializing JSON:

Serialize: Converts a C# object to a JSON string.
Deserialize: Converts a JSON string back into a C# object.

Serialize an object to JSON using `JsonSerializer.Serialize`

The JsonSerializer.Serialize method is used to convert an object into a JSON string representation. This is useful for saving data to files, sending data over networks, or storing data in databases. The Serialize method takes an object as input and returns a JSON string.

The following code demonstrates how to convert an object to a JSON string using JsonSerializer.Serialize:


using System;
using System.Text.Json;
using System.Text.Json.Serialization;

public class Employee
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Address { get; set; }
}

class Program
{
    static void Main()
    {
        var customer = new Employee { Name = "Anette Thomsen", Age = 30, Address = "123 Main St" };
        string jsonString = JsonSerializer.Serialize(customer);
        Console.WriteLine(jsonString);
    }
}

// Output: {"Name":"Anette Thomsen","Age":30,"Address":"123 Main St"}

This code defines a simple Employee class with properties for Name, Age, and Address. The JsonSerializer.Serialize method is used to convert an instance of the Employee class into a JSON string. The output is a JSON representation of the object, which can be easily stored or transmitted.

Deserialize JSON to an object using `JsonSerializer.Deserialize`

The JsonSerializer.Deserialize method is used to convert a JSON string back into a C# object. Deserialization is useful for reading data from files, receiving data from APIs, or processing JSON data in general. The Deserialize method takes a JSON string and the type of the object to be created as input and returns an instance of that object.

The following code demonstrates how to convert a JSON string back into an object using JsonSerializer.Deserialize:


using System;
using System.Text.Json;
using System.Text.Json.Serialization;

public class Employee
{
    public string Name { get; set; } = "Anette Thomsen";
    public int Age { get; set; }
    public string Address { get; set; } = "123 Main St";
}

class Program
{
    static void Main()
    {
        string jsonString1 = "{\"Name\":\"Anette Thomsen\",\"Age\":30,\"Address\":\"123 Main St\"}";
        string jsonString2 = @"{""Name"":""Anette Thomsen"",""Age"":30,""Address"":""123 Main St""}";
        var customer = JsonSerializer.Deserialize<Employee>(jsonString2);
        if (customer != null)
        {
            Console.WriteLine($"Name: {customer.Name}, Age: {customer.Age}, Address: {customer.Address}");
        }
        else
        {
            Console.WriteLine("Deserialization failed.");
        }
    }
}

// Output: Name: Anette Thomsen, Age: 30, Address: 123 Main St

This code defines a JSON string that represents an Employee object. The JsonSerializer.Deserialize method is used to convert the JSON string back into an instance of the Employee class. The JsonSerializer.Deserialize method is generic, meaning you can specify the type of object you expect the JSON string to represent.

In this case, we specify Employee as the type parameter, allowing the method to create an instance of the Employee class based on the JSON data. The Deserialize method returns an instance of the Employee class. The properties of the deserialized object can be accessed directly, as shown in the example. If deserialization fails (e.g., if the JSON string is invalid or doesn't match the expected structure), the method returns null, and you can handle that case accordingly.

Notice that manually constructing the JSON string requires either escape characters or verbatim string literals. The @ symbol before the string indicates that it's a verbatim string literal. Verbatim string literals allow formatting that some people find easier to read.

Summary

In this unit, you learned how to work with JSON data in C# using the System.Text.Json namespace. You explored the concepts of serialization and deserialization, which allow you to convert C# objects to JSON strings and vice versa. You also examined the JsonSerializer class, which provides methods for serializing and deserializing JSON data. You saw examples of how to use the Serialize and Deserialize methods to convert objects to JSON and back, making it easy to work with JSON data in C# applications. Understanding these concepts is essential for working with APIs, data storage, and data interchange in modern software development.

Implement the JsonSerializer class in C# apps

What is serialization?

Examine the System.Text.Json namespace

Examine the JsonSerializer class

Serialize an object to JSON using JsonSerializer.Serialize

Deserialize JSON to an object using JsonSerializer.Deserialize

Summary

Feedback

Examine the `System.Text.Json` namespace

Examine the `JsonSerializer` class

Serialize an object to JSON using `JsonSerializer.Serialize`

Deserialize JSON to an object using `JsonSerializer.Deserialize`