contentcontainer.cs

这是我学习ASP.net Forums的过程中

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;
using System.ComponentModel;

namespace MetaBuilders.WebControls.MasterPages 
{

	/// <summary>
	/// This control serves two distincts purposes:
	/// - it marks the location where the Master Page will be inserted into the Page
	/// - it contains the various Content sections that will be matched to the Master Page's
	///   Region controls (based on their ID's).
	/// </summary>
	public class ContentContainer : PlaceHolder 
	{

		/// <summary>
		/// Creates a new instance of the ContentContainer class.
		/// </summary>
		public ContentContainer() 
		{
			this.MasterPageFile = System.Configuration.ConfigurationSettings.AppSettings["MetaBuilders.WebControls.MasterPages DefaultTemplate"];
		}

		/// <summary>
		/// Only allows <see cref="Content"/> controls to be added.
		/// </summary>
		protected override void AddParsedSubObject(object obj) 
		{
			if (obj is Content) 
			{
				_contents.Add(obj);
			}
			else 
			{
				throw new Exception("The ContentContainer control can only contain content controls");
			}
		}
		private ArrayList _contents = new ArrayList();

		/// <summary>
		/// Overrides the <see cref="Control.OnInit"/> event to load the master page.
		/// </summary>
		protected override void OnInit(EventArgs e) 
		{
			this.LoadMasterPage();
			base.OnInit(e);
		}

		private void LoadMasterPage() 
		{

			if (MasterPageFile == null) 
			{
				throw new Exception("You need to set the MasterPageFile property");
			}

			Control masterPage = Page.LoadControl(MasterPageFile);
			Controls.Add(masterPage);

			MoveContentsIntoRegions();
		}


		private void MoveContentsIntoRegions() 
		{

			foreach (Content content in _contents) 
			{
				Control region = Region.FindRegion(content.ID);
				if ( region == null ) 
				{
					throw new Exception("Could not find matching region for content with ID '" + content.ID + "'");
				}

				// Set the Content control's TemplateSourceDirectory to be the one from the
				// page.  Otherwise, it would end up using the one from the Master Pages user control,
				// which would be incorrect.
				content._templateSourceDirectory = TemplateSourceDirectory;

				region.Controls.Clear();
				region.Controls.Add(content);
			}

		}

		/// <summary>
		/// The path to MasterPage that specifies the layout used to render the contained content.
		/// </summary>
		[
		Category("Behavior"),
		DefaultValue(""),
		Description("The path to MasterPage that specifies the layout used to render the contained content.")
		]
		public string MasterPageFile 
		{
			get 
			{
				return (string)ViewState["MasterPageFile"];
			}
			set 
			{
				ViewState["MasterPageFile"] = value;
				ChildControlsCreated = false;
			}
		}
	}

}