groupradiobutton.cs

C#语言制作asp.net网上商店的

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Globalization;

namespace NetShopForge.Web.UI.WebControls
{
	/// <summary>
	/// GroupRadioButton control is a standard radio-button with the extended 
	/// abilities to be used in groups.
	/// </summary>
	/// <remarks>
	/// Standard <see cref="System.Web.UI.WebControls.RadioButton"/> controls 
	/// cannot be grouped when are placed at the different rows of the DataGrid, 
	/// DataList, Repeater, etc. controls. 
	/// 
	/// The "name" attribute of the radio button HTML control that is rendered 
	/// at the web form after RadioButton control has been executed is depend 
	/// on the UniqueID of the RadioButton. So for the different rows of the 
	/// DataGrid/DataList/Repeater these attributes are different and radio 
	/// buttons do not belong to the same group.
	/// </remarks>	
	[ToolboxData("<{0}:GroupRadioButton runat=server></{0}:GroupRadioButton>")]
	public class GroupRadioButton : RadioButton, IPostBackDataHandler
	{
		public GroupRadioButton() : base()
		{
		}

		#region Properties

		private string Value
		{
			get
			{
				string val = Attributes["value"];
				if(val == null)
					val = UniqueID;
				else
					val = UniqueID + "_" + val;
				return val;
			}
		}

		#endregion
		
		#region Rendering

		protected override void Render(HtmlTextWriter output)
		{
			RenderInputTag(output);
		}

		private void RenderInputTag(HtmlTextWriter htw)
		{
			htw.AddAttribute(HtmlTextWriterAttribute.Id, ClientID);
			htw.AddAttribute(HtmlTextWriterAttribute.Type, "radio");
			htw.AddAttribute(HtmlTextWriterAttribute.Name, GroupName);
			htw.AddAttribute(HtmlTextWriterAttribute.Value, Value);
			if(Checked)
				htw.AddAttribute(HtmlTextWriterAttribute.Checked, "checked");
			if(!Enabled)
				htw.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled");
			
			string onClick = Attributes["onclick"];
			if(AutoPostBack)
			{
				if(onClick != null)
					onClick = String.Empty;
				onClick += Page.GetPostBackClientEvent(this, String.Empty);
				htw.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
				htw.AddAttribute("language", "javascript");
			}
			else
			{
				if(onClick != null)
					htw.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
			}

			if(AccessKey.Length > 0)
				htw.AddAttribute(HtmlTextWriterAttribute.Accesskey, AccessKey);
			if(TabIndex != 0)
				htw.AddAttribute(HtmlTextWriterAttribute.Tabindex, 
					TabIndex.ToString(NumberFormatInfo.InvariantInfo));
			htw.RenderBeginTag(HtmlTextWriterTag.Input);
			htw.RenderEndTag();
		}

		#endregion

		#region IPostBackDataHandler Members

		void IPostBackDataHandler.RaisePostDataChangedEvent()
		{
			OnCheckedChanged(EventArgs.Empty);
		}

		bool IPostBackDataHandler.LoadPostData(string postDataKey, 
			System.Collections.Specialized.NameValueCollection postCollection)
		{
			bool result = false;
			string value = postCollection[GroupName];
			if((value != null) && (value == Value))
			{
				if(!Checked)
				{
					Checked = true;
					result = true;
				}
			}
			else
			{
				if(Checked)
					Checked = false;
			}
			return result;
		}

		#endregion
	}
}