xmlnewsdisplay.cs

ASP.NET服务器控件高级编程电子书

using System;
using System.Xml;
using System.Data;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.Web.UI.Design;

namespace XMLNewsDisplay
{
	[
	Designer("XMLNewsDisplay.Design.XMLNewsDisplayDesigner, XMLNewsDisplay")
	]

	[DefaultProperty("XMLDataSet"),
	ToolboxData("<{0}:XMLNewsDisplay runat=server></{0}:XMLNewsDisplay>")]
	public class XMLNewsDisplay : System.Web.UI.WebControls.WebControl
	{
		private System.Web.UI.WebControls.Unit _width;
		private string _itemheadingcolor;
		private string _itemdescriptioncolor;
		private string _listtitle;
		private System.Data.DataSet  _xmldataset = new System.Data.DataSet();

		public XMLNewsDisplay() : base (HtmlTextWriterTag.Table){}

		public System.Data.DataSet XMLDataSet
		{
			set  {_xmldataset = value;}
		}

		[Bindable(true), Category("Appearance"),
		DefaultValue("")]
		override public System.Web.UI.WebControls.Unit Width
		{
			get  {return _width;}
			set  {_width = value;}
		}

		[Bindable(true), Category("Appearance"),
		DefaultValue("")]
		public string ItemHeadingColor
		{
			get  {return _itemheadingcolor;}
			set  {_itemheadingcolor = value;}
		}

		[Bindable(true), Category("Appearance"),
		DefaultValue("")]
		public string ItemDescriptionColor
		{
			get  {return _itemdescriptioncolor;}
			set  {_itemdescriptioncolor = value;}
		}

		[Bindable(true), Category("Appearance"),
		DefaultValue("")]
		public string ListTitle
		{
			get {return _listtitle;}
			set  {_listtitle = value;}
		}

		protected override void AddAttributesToRender(HtmlTextWriter output)
		{
			output.AddAttribute(HtmlTextWriterAttribute.Width,Width.Value.ToString());
			base.AddAttributesToRender(output);
		}

		protected override void RenderContents(HtmlTextWriter output)
		{
			System.Data.DataTable _datatable = _xmldataset.Tables["item"];
			output.RenderBeginTag(HtmlTextWriterTag.Tr);
			output.RenderBeginTag(HtmlTextWriterTag.Td);
			output.Write(ListTitle);
			output.RenderEndTag();
			output.RenderEndTag();
			for (int i = 0; i < _datatable.Rows.Count; i++)
			{
				output.AddAttribute(HtmlTextWriterAttribute.Bgcolor,ItemHeadingColor);
				output.RenderBeginTag(HtmlTextWriterTag.Tr);
				output.RenderBeginTag(HtmlTextWriterTag.Td);
				output.AddAttribute(HtmlTextWriterAttribute.Href,_datatable.Rows[i]["link"].ToString());
				output.RenderBeginTag(HtmlTextWriterTag.A);
				output.Write(_datatable.Rows[i]["title"]);
				output.RenderEndTag();
				output.RenderEndTag();
				output.RenderEndTag();
				output.AddAttribute(HtmlTextWriterAttribute.Bgcolor,ItemDescriptionColor);
				output.RenderBeginTag(HtmlTextWriterTag.Tr);
				output.RenderBeginTag(HtmlTextWriterTag.Td);
				output.Write(_datatable.Rows[i]["description"]);
				output.RenderEndTag();
				output.RenderEndTag();
			}
			base.RenderContents(output);
		}
	}
}

namespace XMLNewsDisplay.Design 
{
	public class XMLNewsDisplayDesigner : ControlDesigner 
	{
		public XMLNewsDisplayDesigner() {}

		protected override string GetEmptyDesignTimeHtml() 
		{
			string text="Not visible at runtime with current settings";
			return CreatePlaceHolderDesignTimeHtml(text);
		}
	}
}