SharePoint Add Calendar Overlay Programmatically

This is sample of code to add calendar overlay pro grammatically:

using (SPSite site = new SPSite("http://sp2013-tarek294:8000/"))
{
     using (SPWeb web = site.OpenWeb())
    {
          web.AllowUnsafeUpdates = true;
          SPList list = web.Lists["Calendar"];
          SPView m_view = list.Views["Calendar"];
          m_view.CalendarSettings = SerializeAccessors();
          m_view.Update();
          web.AllowUnsafeUpdates = false;

    }
}

private static string SerializeAccessors()
{
 return "<AggregationCalendars>
  <AggregationCalendar Id="{56594c0c-5649-458e-a4e3-939589ddc75d}" Type="SharePoint" Name="Holiday" Description="Holiday" Color="5" AlwaysShow="True" CalendarUrl="/Lists/Calendar/Holiday.aspx">
    <Settings WebUrl="http://sp2013-tarek294:8000" ListId="{6913f374-1a4e-4772-8c5f-9f5d56610f71}" ViewId="{0091da5e-e5a4-4e1f-ab96-19f96eeb59fa}" ListFormUrl="/Lists/Calendar/DispForm.aspx" />
  </AggregationCalendar>
  <AggregationCalendar Id="{d65114d1-cb97-41db-a7eb-7cc3614c957e}" Type="SharePoint" Name="Meeting" Description="Meeting" Color="8" AlwaysShow="True" CalendarUrl="/Lists/Calendar/Meeting.aspx">
    <Settings WebUrl="http://sp2013-tarek294:8000" ListId="{6913f374-1a4e-4772-8c5f-9f5d56610f71}" ViewId="{68513c26-b132-4d9e-b9ca-acc74a4cf1dc}" ListFormUrl="/Lists/Calendar/DispForm.aspx" />
  </AggregationCalendar>
  -->
  <AggregationCalendar Id="{cd33c105-6dd4-4cb9-b6ee-ca26dfcdb70e}" Type="SharePoint" Name="TestView" Description="TestView" Color="3" AlwaysShow="True" CalendarUrl="/Lists/Calendar/TestView.aspx">
    <Settings WebUrl="http://sp2013-tarek294:8000" ListId="{6913f374-1a4e-4772-8c5f-9f5d56610f71}" ViewId="{2D81DDC1-A360-4585-BF4A-7C0E512C7AA8}" ListFormUrl="/Lists/Calendar/DispForm.aspx" />
  </AggregationCalendar>
</AggregationCalendars>"
}

Add SPNavigation Heading programmatically

If you want to add header without link to SharePoint Navigation pro-grammatically,  Need to set some values in the NavigationNode.Properties HashTable.

SPNavigationNode node, node1;             // Get the parent’s top link bar.             SPNavigationNodeCollection topnav = web.Navigation.TopNavigationBar;             // Create the node.             node = new SPNavigationNode("News", "/news", true);             topnav.AddAsLast(node);             node = new SPNavigationNode("Services", string.Empty, true);             node = topnav.AddAsLast(node);             node.MakeHeaderNode();             node1 = new SPNavigationNode("IT Support", "/Services/Lists/Helpdesk Initiation/NewForm.aspx?RootFolder=&source=/", true);             node.Children.AddAsLast(node1); public static class SPNavigationNodeExtensions {     public static void MakeHeaderNode(this SPNavigationNode node)     {         node.Properties["BlankUrl"] = "True";         node.Properties["LastModifiedDate"] = DateTime.Now;         node.Properties["Target"] = "";         node.Properties["vti_navsequencechild"] = "true";         node.Properties["UrlQueryString"] = "";         node.Properties["CreatedDate"] = DateTime.Now;         node.Properties["Description"] = "";         node.Properties["UrlFragment"] = "";         node.Properties["NodeType"] = "Heading";         node.Properties["Audience"] = "";         node.Update();     } }

As you can see, the “BlankUrl'” = True, and NodeType = “Heading”.