What is a new working way to deepcopy a class I made?

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I can't find any working way I've been searching for hours.

What I have tried:

public static T Clone<T>(T obj)
        {
            DataContractSerializer dcSer = new DataContractSerializer(obj.GetType());
            MemoryStream memoryStream = new MemoryStream();

            dcSer.WriteObject(memoryStream, obj);
            memoryStream.Position = 0;

            T newObject = (T)dcSer.ReadObject(memoryStream);
            return newObject;
        }

public static class ExtensionMethods
{
    // Deep clone
    public static T DeepClone<T>(this T a)
    {
        using (MemoryStream stream = new MemoryStream())
        {
            BinaryFormatter formatter = new BinaryFormatter();
            formatter.Serialize(stream, a);
            stream.Position = 0;
            return (T) formatter.Deserialize(stream);
        }
    }
}
which extends any class that's been marked as [Serializable] with a DeepClone method

MyClass copy = obj.DeepClone();

Posted 11-Sep-22 21:05pm

FierceLion

Updated 20-Sep-22 9:12am

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Member 15627495 12-Sep-22 3:27am

a class can't be copied.
an object can be copied.

class t A = new class t;class t B = A;

FierceLion 12-Sep-22 8:44am

Sorry I didn't understand the sample code, would you please explain?

charles henington 17-Sep-22 12:00pm

a class can be copied using the System.Runtime.Serialization.Formatters.Binary.BinaryFormatter class as the example shows above as long as the class is marked with the [System.Serializable] attribute. The example you provide simply passes one reference to another. With a deep copy like the example above you can save an instance of the class even when there's no reference to point to.

FierceLion 18-Sep-22 20:55pm

This seems to have worked well for me, please submit it as an answer so I accept it:

The class must be marked with the [System.Serializable] attribute:

public static class Helper
{
public static T CreateDeepCopy<t>(T obj)
{
using (var ms = new MemoryStream())
{
IFormatter formatter = new BinaryFormatter();
formatter.Serialize(ms, obj);
ms.Seek(0, SeekOrigin.Begin);
return (T)formatter.Deserialize(ms);
}
}
}

From here: https://levelup.gitconnected.com/5-ways-to-clone-an-object-in-c-d1374ec28efa

2 solutions

Solution 1

BinaryFormatter is depreciated and in the latest release obsolete: Breaking change: BinaryFormatter serialization methods are obsolete and prohibited in ASP.NET apps - .NET | Microsoft Docs[^]

Have you seen this: 5 Ways to Clone An Object in C#[^] - I'd probably go with the XML version.

Posted 11-Sep-22 21:48pm

OriginalGriff

Comments

FierceLion 12-Sep-22 3:53am

https://imgur.com/a/yWEPglN

FierceLion 12-Sep-22 10:32am

First I had this error:
System.InvalidOperationException: 'DisksColorsFromTopAndSide.FormMain.oneTower cannot be serialized because it does not have a parameterless constructor.'

So I made a parameterless constructor, then I had this error:

System.InvalidOperationException: 'DisksColorsFromTopAndSide.FormMain.oneTower cannot be serialized because it does not have a parameterless constructor.'

So I made as public the class I want to duplicate.

Now it duplicates both the colors list and the int lists, the int list gets its values but the colors are all 0,0,0 in RGB but with the same number of elements as the main class object.

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charles henington · Accepted Answer · 2022-09-20T09:12:00

Simply add

C#

[System.Serializable]

attribute to the class that you wish to Serialize.
Feel free to add these to your extensions

C#

public static byte[] Clone<T>(this T a)
        {
            using (MemoryStream stream = new MemoryStream())
            {
                BinaryFormatter formatter = new BinaryFormatter();
                formatter.Serialize(stream, a);
                return stream.ToArray();
            }
        }
        public static T FromClone<T>(this byte[] array)
        {
            using (MemoryStream stream = new MemoryStream(array))
            {
                BinaryFormatter formatter = new BinaryFormatter();
                return (T)formatter.Deserialize(stream);
            }
        }

Now you should be able to save the Clone and load an instance of cloned class from file.
As you wish sir.

public static class Helper { public static T CreateDeepCopy<t>(T obj) { using (var ms = new MemoryStream()) { IFormatter formatter = new BinaryFormatter(); formatter.Serialize(ms, obj); ms.Seek(0, SeekOrigin.Begin); return (T)formatter.Deserialize(ms); } } }

From here: https://levelup.gitconnected.com/5-ways-to-clone-an-object-in-c-d1374ec28efa

One thing that you will see using BinaryFormatter is that the output can get exceptionally large. I will provide 2 more helpers to help you compress them using System.IO.Compression

C#

public static byte[] CompressClone<T>(this T a)
        {
            byte[] clone = a.Clone<T>();
            using (var compressedStream = new MemoryStream())
            using (var zipStream = new GZipStream(compressedStream, CompressionMode.Compress))
            {
                zipStream.Write(clone, 0, clone.Length);
                zipStream.Close();
                return compressedStream.ToArray();
            }
        }
        public static T DecompressClone<T>(this byte[] array)
        {
            byte[] clone = null;
            using (var compressedStream = new MemoryStream(array))
            using (var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
            using (var resultStream = new MemoryStream())
            {
                zipStream.CopyTo(resultStream);
                clone = resultStream.ToArray();
            }
            return clone.FromClone<T>();
        }