How to increase number of characters when reading data from

I work in windows from c# vs 2015

i read data from scanner bar code reader directly to my windows

without using text box box but i face problem

i need to increase number of character when receiving to 200 character

so that how to increase that please ?

code below working success but it read only 13 character

i need to increase it to 200 character or less so that how ?

public partial class Form1 : Form
    {
        DateTime _lastKeystroke = new DateTime(0);
        List<char> _barcode = new List<char>(10);
        public Form1()
        {
            InitializeComponent();
        }

       

        private void Form1_KeyPress(object sender, KeyPressEventArgs e)
        {
            TimeSpan elapsed = (DateTime.Now - _lastKeystroke);
            if (elapsed.TotalMilliseconds > 100)
                _barcode.Clear();

            _barcode.Add(e.KeyChar);
            _lastKeystroke = DateTime.Now;

            if (e.KeyChar == 13 && _barcode.Count > 0)
            {
                string msg = new String(_barcode.ToArray());
               
                label1.Text = msg;
                _barcode.Clear();
            }
        }
    }
}

so that code above can read but 13 character only

i need to increase it to 200 character or less .

bar code scanner is working as USB keyboard as HID keyboard read qr code