C# Problem mit Dictionary<string, struct>

    public partial class Form1 : Form
    {
        struct Channel
        {
            static string titel;
            static string admin;
            static string pw;
            public Channel(bool SetEmpty)
            {
                if (SetEmpty == true)
                {
                    titel = null;
                    admin = null;
                    pw = null;
                }
            }
            public static string[] Refresh()
            {
                string[] Out = new string[3];
                Out[0] = titel;
                Out[1] = admin;
                Out[2] = pw;
                return Out;
            }
            public string Titel
            {
                get { return titel; }
                set { titel = value; }
            }
            public string Admin
            {
                get { return admin; }
                set { admin = value; }
            }
            public string PW
            {
                get { return pw; }
                set { pw = value; }
            }
        }
        static Dictionary<string, Channel> ChannelList = new Dictionary<string, Channel>(); 
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string ChannelName = textBox1.Text;
            Channel I = new Channel(true);
            I.Titel = textBox2.Text;
            I.Admin = textBox3.Text;
            I.PW = textBox4.Text;
            ChannelList.Add(ChannelName, I);
            listBox1.Items.Clear();
            listBox1.Items.AddRange(Channel.Refresh());
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
            RefreshListView();
        }
        void RefreshListView()
        {
            listView1.Items.Clear();
            foreach (string ChannelName in ChannelList.Keys)
            {
                Channel I = ChannelList[ChannelName];
                listView1.Items.Add(ChannelName);
                listView1.Items[listView1.Items.Count - 1].SubItems.Add(I.Titel);
                listView1.Items[listView1.Items.Count - 1].SubItems.Add(I.Admin);
                listView1.Items[listView1.Items.Count - 1].SubItems.Add(I.PW);
            }
        }
    }

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace DictionaryTest
{
    public partial class Form1 : Form
    {
       struct Channel
        {
           string titel;
           string admin;
           string pw;

            public Channel(String _titel, String _admin, String _pw)
            {
                titel = _titel;
                admin = _admin;
                pw = _pw;
            }

            public string[] ToStrings()
            {
                string[] Out = new string[3];
                Out[0] = titel;
                Out[1] = admin;
                Out[2] = pw;
                return Out;
            }

            public string Titel
            {
                get { return titel; }
                set { titel = value; }
            }
            public string Admin
            {
                get { return admin; }
                set { admin = value; }
            }
            public string PW
            {
                get { return pw; }
                set { pw = value; }
            }
        }
        static Dictionary<string, Channel> ChannelList = new Dictionary<string, Channel>(); 
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string ChannelName = textBox1.Text;
            Channel I = new Channel(textBox2.Text, textBox3.Text, textBox4.Text);
            ChannelList.Add(ChannelName, I);
            listBox1.Items.Clear();
            listBox1.Items.AddRange(I.ToStrings());
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
            RefreshListView();
        }
        void RefreshListView()
        {
            listView1.Items.Clear();
            foreach (string ChannelName in ChannelList.Keys)
            {
                Channel I = ChannelList[ChannelName];
                ListViewItem li = new ListViewItem(ChannelName);
                li.SubItems.Add(I.Titel);
                li.SubItems.Add(I.Admin);
                li.SubItems.Add(I.PW);
                
                listView1.Items.Add(li);
            }
        }
    }
}

    class Data
    {
        public Dictionary<string, Channel> ChannelList = new Dictionary<string, Channel>();
    }
    class Channel
    {
        string titel;
        string admin;
        string pw;

        public string[] ToStrings()
        {
            string[] Out = new string[3];
            Out[0] = titel;
            Out[1] = admin;
            Out[2] = pw;
            return Out;
        }
        public string Titel
        {
            get { return titel; }
            set { titel = value; }
        }
        public string Admin
        {
            get { return admin; }
            set { admin = value; }
        }
        public string PW
        {
            get { return pw; }
            set { pw = value; }
        }
    }

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Data Daten = new Data();
            string ChannelName = textBox1.Text;
            Channel I = new Channel();
            I.Titel = textBox2.Text;
            I.Admin = textBox3.Text;
            I.PW = textBox4.Text;
            Daten.ChannelList.Add(ChannelName, I);
            listBox1.Items.Clear();
            listBox1.Items.AddRange(I.ToStrings());
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
            RefreshListView();
        }
        void RefreshListView()
        {
            Data Daten = new Data(); //geht nicht, erhalte nicht den aktuellen Dictionary-Wert
            listView1.Items.Clear();
            foreach (string ChannelName in Daten.ChannelList.Keys)
            {
                Channel I = Daten.ChannelList[ChannelName];
                ListViewItem li = new ListViewItem(ChannelName);
                li.SubItems.Add(I.Titel);
                li.SubItems.Add(I.Admin);
                li.SubItems.Add(I.PW);

                listView1.Items.Add(li);
            }
        }

class Form1 
{
    Data Daten;
    public Form1
    {
        InitializeComponent();
        Daten = new Data();
    }
    ... 
}

    public partial class Form1 : Form
    {
        Data Daten;
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Daten = new Data();
            string ChannelName = textBox1.Text;
            Channel I = new Channel();
            I.Titel = textBox2.Text;
            I.Admin = textBox3.Text;
            I.PW = textBox4.Text;
            Daten.ChannelList.Add(ChannelName, I);
            ...
        }
        void RefreshListView()
        {
            Daten = new Data();
            ...
        }
    }

namespace Chat_Server
{
    class Data
    {
         Variables Vars;
         Vars = Instanz.Main.Invoke(new CallbackVariables(Instanz.Main.RecieveVariables));
         //funtioniert nicht
    }
    delegate Variables CallbackVariables();
    public partial class Main : Form
    {
        Variables Vars;
        public Variables RecieveVariables()
        {
            return Vars;
        }
    }
    public class Variables
    {
         //Variablen
    }
}