Accessing SharePoint Quick Launch menu (SPNavigation.QuickLaunch) using C#:

Accessing SharePoint Quick Launch menu (SPNavigation.QuickLaunch) using C#:
With the help of SPNavigation, we will be able to access the Quick Launch menu of SharePoint site. Sometimes we need to show/hide Quick Launch menu item, so with the help of SPNavigation. QuickLaunch, we can loop through Quick Launch menu item.
In this example we will access Quick Launch menu:

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Office.Server;
using Microsoft.Office.Server.Administration;
using Microsoft.Office.Server.UserProfiles;
using Microsoft.SharePoint;
using System.Web;
using Microsoft.SharePoint.Navigation;


namespace GetQuickLaunch
{
    class Program
    {
        static void Main(string[] args)
        {

            using (SPSite site = new SPSite("http://amitkumarmca04.blogspot.com/"))
            {
                using (SPWeb web = site.OpenWeb())
                {
                    SPNavigationNodeCollection qlNodes = web.Navigation.QuickLaunch;
                    foreach (SPNavigationNode node in qlNodes)
                    {
                        Console.WriteLine(node.Title + "--" + node.Url);
                    }
                }
            }
        }
    }
}

Reference: MSDN