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 System.Reflection;

namespace WinFormDemo
{
    public partial class FrmMain : Form
    {
        public FrmMain()
        {
            InitializeComponent();
        }

        private void tvMenu_NodeMouseDoubleClick(object sender, TreeNodeMouseClickEventArgs e)
        {
            if (null != e.Node.Parent)
            {
                if (0 == e.Node.Nodes.Count)
                {
                    ShowForm(e.Node.Text);
                }
            }
        }

        private void ShowForm(string strFormName)
        {
            Form frm = GetForm(strFormName);
            frm.BringToFront();
            frm.Show();
        }

        private Form GetForm(string strFormName)
        {
            Control.ControlCollection ctrls = pnlCentral.Controls;
            if (ctrls.ContainsKey(strFormName))
            {
                return ctrls[strFormName] as Form;
            }
            else
            {
                Assembly assembly = Assembly.GetExecutingAssembly();
                Type type = assembly.GetTypes().Where(item => item.Name.Equals(strFormName)).FirstOrDefault();
                
                Form frm = assembly.CreateInstance(type.FullName) as Form;
                frm.Name = strFormName;
                frm.TopLevel = false;
                frm.Dock = DockStyle.Fill;
                frm.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
                pnlCentral.Controls.Add(frm);

                return frm;
            }
        }
    }
}