C# Json Examples

C# Basic

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Json Serialize with null property in C#

To ignore null properties during JSON serialization using Json.NET, you can use the NullValueHandling option with the value NullValueHandling.Ignore. Here's an example:

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

Person person = new Person {
    Name = "John",
    Age = 30
};

string json = JsonConvert.SerializeObject(person, Formatting.Indented,
    new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });

Console.WriteLine(json);

In this example, the Address property is null, but it will be ignored during serialization, and won't be included in the resulting JSON.

To set a null property with a default empty value during JSON serialization using Json.NET, you can use the DefaultValueHandling option with the value DefaultValueHandling.Empty. Here's an example:

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

Person person = new Person {
    Name = "John",
    Age = 30,
    Address = null
};

string json = JsonConvert.SerializeObject(person, Formatting.Indented,
    new JsonSerializerSettings { 
        DefaultValueHandling = DefaultValueHandling.Populate,
        NullValueHandling = NullValueHandling.Include
    });

Console.WriteLine(json);

In this example, the Address property is null, but it will be serialized with a default empty value, and will be included in the resulting JSON. Note that we also set NullValueHandling to Include to include the null values in the JSON.

C# JSON serialize null properties:

Basic example of serializing an object with null properties to JSON.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person);

Json.NET serialize null properties example:

Using Json.NET to serialize an object with null properties to JSON.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person);

Include null properties in JSON serialization C#:

Configuring Json.NET to include null properties during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Include });

Serialize null values in C# JSON:

Manually handling null values during JSON serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });

C# Newtonsoft.Json serialize null property:

Serializing an object with null properties to JSON using Json.NET.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person);

Handling null properties during JSON serialization in C#:

Implementing custom logic to handle null properties during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    private int? _age;

    public int? Age
    {
        get { return _age; }
        set { _age = value ?? -1; }
    }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person);

JsonSerializerSettings NullValueHandling C#:

Using JsonSerializerSettings to configure null value handling during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
var jsonSettings = new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore };
string jsonString = JsonConvert.SerializeObject(person, jsonSettings);

Serialize C# object with nullable properties to JSON:

Serializing an object with nullable properties, including null values.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Include });

C# JSON.NET serialize null property to JSON string:

Serializing an object with null properties to a JSON string using Json.NET.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person);

Include null properties in JSON output using JsonConvert in C#:

Configuring Json.NET to include null properties in JSON output.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Include });

Newtonsoft.Json JsonNullValueHandling setting in C#:

Using JsonNullValueHandling setting to control null property handling in JSON serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
var jsonSettings = new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore, DefaultValueHandling = DefaultValueHandling.Ignore };
string jsonString = JsonConvert.SerializeObject(person, jsonSettings);

Handling null properties with DataContractJsonSerializer in C#:
- Handling null properties during JSON serialization using DataContractJsonSerializer.
- Code snippet:
```
[DataContract]
public class Person
{
    [DataMember]
    public string Name { get; set; }

    [DataMember]
    public int? Age { get; set; }
}
```
C# JSON serialization with null properties and DefaultValueAttribute:
- Using DefaultValueAttribute to specify default values for null properties during serialization.
- Code snippet:
```
public class Person
{
    public string Name { get; set; }

    [DefaultValue(-1)]
    public int? Age { get; set; }
}
```

Serialize object with null properties using JsonConverter in C#:

Applying a custom JsonConverter to handle null properties during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

public class NullablePropertyConverter : JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var jsonObject = JObject.FromObject(value);
        jsonObject.PropertyValues()
            .Where(p => p.Value.Type == JTokenType.Null)
            .ToList()
            .ForEach(p => p.Remove());
        jsonObject.WriteTo(writer);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override bool CanRead => false;

    public override bool CanConvert(Type objectType)
    {
        return true;
    }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person, new NullablePropertyConverter());

Include null properties in JSON using System.Text.Json in C#:

Configuring System.Text.Json to include null properties during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
var jsonSerializerOptions = new JsonSerializerOptions { DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull };
string jsonString = JsonSerializer.Serialize(person, jsonSerializerOptions);

JsonSerializer.NullValueHandling property in C#:

Utilizing JsonSerializer.NullValueHandling property to control null property handling during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
var jsonSerializer = new JsonSerializer { NullValueHandling = NullValueHandling.Include };
string jsonString = JsonConvert.SerializeObject(person, jsonSerializer);

Serialize object with null properties using custom contract resolver in C#:

Implementing a custom contract resolver to handle null properties during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
var jsonSettings = new JsonSerializerSettings
{
    ContractResolver = new NullablePropertyContractResolver()
};
string jsonString = JsonConvert.SerializeObject(person, jsonSettings);

Handling null properties with JsonIgnoreAttribute in C#:

Applying JsonIgnoreAttribute to exclude properties with null values during serialization.

Code snippet:

public class Person
{
    public string Name { get; set; }

    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public int? Age { get; set; }
}

var person = new Person { Name = "John", Age = null };
string jsonString = JsonConvert.SerializeObject(person);

Serialize object with null properties to JSON array in C#:

Serializing an object with null properties to a JSON array using Json.NET.

Code snippet:

public class Person
{
    public string Name { get; set; }
    public int? Age { get; set; }
}

var people = new List<Person>
{
    new Person { Name = "John", Age = null },
    new Person { Name = "Jane", Age = 25 }
};
string jsonArray = JsonConvert.SerializeObject(people);