databoundstate.cs

asp.net技术内幕的书配源码

using System;
using System.Web;
using System.Web.UI;
using System.Collections;

namespace myControls {

	[ParseChildren(true)]
	public class DataBoundState : Control {

		private IEnumerable _dataSource;
		private ITemplate _itemTemplate;

		public IEnumerable DataSource {
			get {
				return _dataSource;
			}
			set {
				_dataSource = value;
			}
		}


		protected override void OnDataBinding(EventArgs e) {
			IEnumerator objDataEnum;
			DataBoundStateItem objItem;
			int intCounter=0;
    
			if (DataSource!=null) {
				Controls.Clear();
				ClearChildViewState();
				objDataEnum = DataSource.GetEnumerator();
				while (objDataEnum.MoveNext()) {
					objItem = new DataBoundStateItem( objDataEnum.Current );
					ItemTemplate.InstantiateIn( objItem );
					Controls.Add( objItem );
					intCounter++;
				}
				ViewState["NumItems"] = intCounter;
				ChildControlsCreated = true;
			}
		}


		protected override void CreateChildControls() {
			object objNumItems;
			int intItemCount;
			DataBoundStateItem objItem;
		
			objNumItems = ViewState["NumItems"];

			if (objNumItems != null) {
				Controls.Clear();
				intItemCount = (int)objNumItems;
				for (int i=0;i<intItemCount;i++) {
					objItem  = new DataBoundStateItem(null);
					ItemTemplate.InstantiateIn( objItem );
					Controls.Add( objItem );
				}
			}
		}

		[TemplateContainer(typeof(DataBoundStateItem))]
		public ITemplate ItemTemplate {
			get {
				return _itemTemplate;
			}
			set {
				_itemTemplate = value;
			}
		}
	}


	public class DataBoundStateItem : Control, INamingContainer {

		private object _DataItem;

		public DataBoundStateItem( object DataItem ) : base() {
			_DataItem = DataItem;
		}

		public object DataItem {
			get {
				return _DataItem;
			}
		}
	}
}