HtmlInputRadioButton.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / UI / HtmlControls / HtmlInputRadioButton.cs / 1 / HtmlInputRadioButton.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 * HtmlInputRadioButton.cs 
 *
 * Copyright (c) 2000 Microsoft Corporation 
 */

namespace System.Web.UI.HtmlControls {
    using System.ComponentModel; 
    using System;
    using System.Collections; 
    using System.Collections.Specialized; 
    using System.Web;
    using System.Web.UI; 
    using System.Security.Permissions;


///  
///    
///       The  class defines the methods, 
///       properties, and events for the HtmlInputRadio control. This class allows 
///       programmatic access to the HTML <input type=
///       radio> 
///       element on the server.
///    
/// 
    [ 
    DefaultEvent("ServerChange"),
    SupportsEventValidation, 
    ] 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    public class HtmlInputRadioButton : HtmlInputControl, IPostBackDataHandler {

        private static readonly object EventServerChange = new object();
 
        /*
         * Creates an intrinsic Html INPUT type=radio control. 
         */ 

        public HtmlInputRadioButton() : base("radio") { 
        }

        /*
         * Checked property. 
         */
 
        ///  
        ///    
        ///       Gets or sets a value indicating whether a radio button is 
        ///       currently selected or not.
        ///    
        /// 
        [ 
        WebCategory("Default"),
        DefaultValue(""), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden) 
        ]
        public bool Checked { 
            get {
                string s = Attributes["checked"];
                return((s != null) ? (s.Equals("checked")) : false);
            } 
            set {
                if (value) 
                    Attributes["checked"] = "checked"; 
                else
                    Attributes["checked"] = null; 
            }
        }

 
        /// 
        ///     
        ///       Gets the value of the HTML 
        ///       Name attribute that will be rendered to the browser.
        ///     
        /// 
        public override string Name {
            get {
                string s = Attributes["name"]; 
                return ((s != null) ? s : String.Empty);
            } 
            set { 
                Attributes["name"] = MapStringAttributeToString(value);
            } 
        }


        ///  
        ///    
        ///       Gets or sets the contents of a text box. 
        ///     
        /// 
        public override string Value { 
            get {
                string val = base.Value;

                if (val.Length != 0) 
                    return val;
 
                val = ID; 
                if (val != null)
                    return val; 

                // if specific value is not provided, use the UniqueID
                return UniqueID;
            } 
            set {
                base.Value = value; 
            } 
        }
 
        // Value that gets rendered for the Name attribute
        internal override string RenderedNameAttribute {
            get {
                // For radio buttons, we must make the name unique, but can't just use the 
                // UniqueID because all buttons in a group must have the same name.  So
                // we replace the last part of the UniqueID with the group Name. 
                string name = base.RenderedNameAttribute; 
                string uid = UniqueID;
                int lastColon = uid.LastIndexOf(IdSeparator); 
                if (lastColon >= 0)
                    name = uid.Substring(0, lastColon+1) + name;
                return name;
            } 
        }
 
 
        [
        WebCategory("Action"), 
        WebSysDescription(SR.Control_OnServerCheckChanged)
        ]
        public event EventHandler ServerChange {
            add { 
                Events.AddHandler(EventServerChange, value);
            } 
            remove { 
                Events.RemoveHandler(EventServerChange, value);
            } 
        }

        /*
         * This method is invoked just prior to rendering. 
         */
 
        ///  
        /// 
        ///  
        protected internal override void OnPreRender(EventArgs e) {
            base.OnPreRender(e);

            if (Page != null && !Disabled) { 
                Page.RegisterRequiresPostBack(this);
 
                Page.RegisterEnabledControl(this); 
            }
 
            // if no change handler, no need to save posted property
            if (Events[EventServerChange] == null && !Disabled) {
                ViewState.SetItemDirty("checked",false);
            } 
        }
 
        /* 
         * Method used to raise the OnServerChange event.
         */ 

        /// 
        /// 
        protected virtual void OnServerChange(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventServerChange];
            if (handler != null) handler(this, e); 
        } 

 
        /// 
        /// 
        /// 
        protected override void RenderAttributes(HtmlTextWriter writer) { 
            if (Page != null) {
                Page.ClientScript.RegisterForEventValidation(Value, RenderedNameAttribute); 
            } 

            writer.WriteAttribute("value", Value); 
            Attributes.Remove("value");
            base.RenderAttributes(writer);
        }
 
        /*
         * Method of IPostBackDataHandler interface to process posted data. 
         * RadioButton determines the posted radio group state. 
         */
 
        /// 
        /// 
        /// 
        bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection) { 
            return LoadPostData(postDataKey, postCollection);
        } 
 

        ///  
        /// 
        /// 
        protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
            string postValue = postCollection[RenderedNameAttribute]; 
            bool valueChanged = false;
            if ((postValue != null) && postValue.Equals(Value)) { 
                if (Checked == false) { 

                    ValidateEvent(Value, RenderedNameAttribute); 

                    Checked = true;
                    // only fire change event for RadioButton that is being checked
                    valueChanged = true; 
                }
            } 
            else { 
                if (Checked == true) {
                    Checked = false; 
                }
            }

            return valueChanged; 
        }
 
        /* 
         * Method of IPostBackDataHandler interface which is invoked whenever posted data
         * for a control has changed.  RadioButton fires an OnServerChange event. 
         */

        /// 
        ///  
        /// 
        void IPostBackDataHandler.RaisePostDataChangedEvent() { 
            RaisePostDataChangedEvent(); 
        }
 

        /// 
        /// 
        ///  
        protected virtual void RaisePostDataChangedEvent() {
            OnServerChange(EventArgs.Empty); 
        } 
    }
}

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