MainForm()

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;
using WindowsFormsApplication3.Model;
using WindowsFormsApplication3.Enums;
using WindowsFormsApplication3.FormPage;
using WindowsFormsApplication3.DataStorge;
using System.Threading;

namespace WindowsFormsApplication3
{
    public partial class MainForm : Form
    {
        protected static readonly Color[] TREE_VIEW_FORE_COLOR = new Color[] { Color.Black, Color.Black, Color.Black, Color.Red, Color.Black };

        protected BaseWorkerForm activeForm;
        protected Dictionary<string, BaseWorkerForm> formDictionary;
        protected Dictionary<string, TreeNode> nodeDictionary;
        protected FormStatus status;
        protected CheckoutContext checkoutContext;
        public CheckoutContext CheckoutContext
        {
            get { return checkoutContext; }
        }

        public MainForm():base()
        {
            this.checkoutContext = new CheckoutContext();
            InitializeComponent();
        }

        protected void BuildNodeDictionary(TreeNodeCollection nodes) {
            foreach (TreeNode node in nodes) {
            if(formDictionary.ContainsKey(node.Name)){
                node.Tag=formDictionary[node.Name];
                nodeDictionary.Add(node.Name,node);
            }
            BuildNodeDictionary(node.Nodes);
            }
        }

        private void buttonTroubleshoot_Click(object sender, EventArgs e)
        {
            Execute();
        }

        public void Execute() {
            status = FormStatus.Processing;
            buttonTroubleshoot.Enabled = false;
            foreach (var childf in checkoutContext.formHierachy)
            {
                childf.childForm.ResetForm();;
                childf.childForm.RefreshForm();
            }
            RefreshForm();
            ExecuteForm();

        }

        protected void ExecuteForm() {
            foreach (var childf in checkoutContext.formHierachy)
            {

                ThreadPool.QueueUserWorkItem(new WaitCallback(childf.childForm.Execute),null);
            }
        }

        public void ChildFormStatusChanged() {
           // RefreshForm();
        }
        private void MainForm_Load(object sender, System.EventArgs e) {

            nodeDictionary=new Dictionary<string,TreeNode>();
            checkoutContext.formHierachy.Add(new FormHierachy("null", new IntroductionForm(checkoutContext, CheckoutStep.Introduction)));
            //checkoutContext.formHierachy.Add(new FormHierachy("IntroductionForm", new ClientForm(checkoutContext, CheckoutStep.Client)));
            //checkoutContext.formHierachy.Add(new FormHierachy("IntroductionForm", new ServerForm(checkoutContext, CheckoutStep.Server)));
            //checkoutContext.formHierachy.Add(new FormHierachy("ServerForm", new CellsForm(checkoutContext, CheckoutStep.Cells)));
            //checkoutContext.formHierachy.Add(new FormHierachy("ServerForm", new VolumesForm(checkoutContext, CheckoutStep.Volumes)));
            checkoutContext.formHierachy.Add(new FormHierachy("ClientForm", new OperationSystemForm(checkoutContext, CheckoutStep.OperationSystem)));

            foreach (var childf in checkoutContext.formHierachy)
            {
                childf.childForm.TopLevel = false;
                childf.childForm.Dock = DockStyle.Fill;
                childf.childForm.Visible = true;
                childf.childForm.FormBorderStyle = FormBorderStyle.None;
            }

            formDictionary=new Dictionary<string,BaseWorkerForm>();
            foreach (var childf in checkoutContext.formHierachy)
            {
                formDictionary.Add(childf.childForm.Text, childf.childForm);
                childf.childForm.FormStatusChanged += ChildFormStatusChanged;
            }
            activeForm = formDictionary["IntroductionForm"] as BaseWorkerForm;
            splitContainer1.Panel2.Controls.Add(activeForm);
            BuildNodeDictionary(treeViewSteps.Nodes);
            treeViewSteps.ImageList = ImageConstants.IMAGE_LIST_FORM_STATUS;
            treeViewSteps.ExpandAll();
            RefreshForm();
        }

        public void RefreshForm() {
            richTextBox.Clear();
            RefreshTreeNodes(treeViewSteps.Nodes);
            foreach(LogEntry le in checkoutContext.logData.logList){
                richTextBox.AppendText(le.ToString());
            }
        }

        public void RefreshTreeNodes(TreeNodeCollection nodes) {
            foreach (TreeNode node in nodes) {
                BaseWorkerForm form = node.Tag as BaseWorkerForm;
                FormStatus formstatus = form == null ? FormStatus.Waiting : form.Status;
                node.ForeColor = TREE_VIEW_FORE_COLOR[(int)formstatus];
                node.SelectedImageIndex = node.ImageIndex = (int)formstatus;
                RefreshTreeNodes(node.Nodes);
            }
        }

        private void treeViewSteps_AfterSelect(object sender, TreeViewEventArgs e)
        {
            TreeNode treeNode = e.Node;
            if (activeForm != null)
                splitContainer1.Panel2.Controls.Remove(activeForm);
            activeForm = treeNode.Tag as BaseWorkerForm;
            if (activeForm != null)
                splitContainer1.Panel2.Controls.Add(activeForm);
        }
     }
}

MainForm()