How to Convert an Object to a Byte Array in C#

How to convert an object to a byte array in C#?

The most common approach to convert an object to a byte array in the .NET Framework is to use the BinaryFormatter.

This method requires the object to be marked as [Serializable], and it allows for easy serialization of the object into a byte array using a MemoryStream.

C# Object to Byte Array

For example, c# convert object to byte array

// c# convert object to byte array
// c# class to byte array
public byte[] ObjectToByteArray<T>(T obj)
{
    if (obj != null)
    {
        using (MemoryStream ms = new MemoryStream())
        {
            // c# serialize object to byte array
            new BinaryFormatter().Serialize(ms, obj);
            // c# to byte array
            return ms.ToArray();
        }
    }
    return null;
}

Usage

[Serializable]
public class People
{
    public int Id { get; set; }
    public string Name { get; set; }
}

//Main.cs

People obj = new People { Id = 1, Name = "Tom" };
// object to byte array c#
byte[] byteArray = ObjectToByteArray(obj);

Ensure that the class you are serializing is marked with [Serializable] if you are using BinaryFormatter.

C# Byte Array to Object

To convert a byte array back into an object in C#, you can create a method that deserializes the byte array using the BinaryFormatter.

For example, c# convert byte array to an object

// c# convert byte array to object
public T ByteArrayToObject<T>(byte[] byteArray)
{
    if (byteArray == null || byteArray.Length == 0)
    {
        throw new ArgumentException("Byte array is null or empty.");
    }

    using (MemoryStream ms = new MemoryStream(byteArray))
    {
        // c# deserialize byte array to object
        BinaryFormatter formatter = new BinaryFormatter();
        return (T)formatter.Deserialize(ms);
    }
}

Usage

[Serializable]
public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
}

public void Test()
{
    // Original object
    Customer obj = new Customer{ Id = 1, Name = "Lucy" };

    // Convert object to byte array
    byte[] byteArray = ObjectToByteArray(obj);

    // Convert byte array back to object
    Example deserializedObj = ByteArrayToObject<Customer>(byteArray);

    Console.WriteLine($"Id: {deserializedObj.Id}, Name: {deserializedObj.Name}");
}

The BinaryFormatter is marked as obsolete in .NET 5 and later due to security concerns. It's better to use alternatives like System.Text.Json, XmlSerializer, or DataContractSerializer if you're targeting newer frameworks or handling sensitive data.