Data Between Source Files in C#

I'm sorry for the rudimentary question, but I'd like to ask you a question.

languages:C#

We are currently working on an application that runs in the following order.
Read file data → Convert read data → Convert and output
This is what I've done. I've made each process a separate file and a separate class for my study.

I would like to read, convert, and output file data into a variable called ByteWork.
How
the location of the ByteWork instance at that time and the argument return value when calling each function, etc. I'm at a standstill to see if it works well.
The number of elements to be taken when you instance ByteWork is to take the number of bytes of the file data that you read, and I put it in the Read class for ByteWork to remember...
I think it will disappear if I skip Re.ReadFileMethod().

Thank you for your guidance and encouragement on how to do it well.

Indicates the file configuration and the program that has questions.
I'm sorry for the program on the way. Please forgive me.
Form1.cs:main, invoking each action
Read.cs:loading file data
Convert.cs:convert read data
Out.cs:output

Form1.cs↓↓↓↓↓↓

publicForm1()
    {
        InitializeComponent();
    }

    // Press button to start processing
    private void ConvertB_Click(object sender, EventArgse)
    {
        // loading
        Read Re=new Read();
        Re.ReadFileMethod();
        // Conversion
        Convert Cn = new Convert();
        Cn.ConvertMethod();
        // Fishing
        OutPutOp = new OutPut();
        Op.OutputMethod();
    }
}

Read.cs↓↓↓↓↓↓

public class Read
{
    public void ReadFileMethod()
    {
        FileStream fs=new FileStream(@"C:\cWork\bin.bin", FileMode.Open);
        byte [ ] ByteWork = new byte [fs.Length];
        fs.Read (ByteWork, 0, ByteWork.Length);
        fs.Close();
    }
}