HtmlInputCheckBox.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 / HtmlInputCheckBox.cs / 1 / HtmlInputCheckBox.cs
                        

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

/* 
 * HtmlInputCheckBox.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.Globalization;
    using System.Web; 
    using System.Web.UI;
    using System.Security.Permissions;

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

        private static readonly object EventServerChange = new object(); 

        /* 
         *  Creates an intrinsic Html INPUT type=checkbox control. 
         */
 
        /// 
        /// Initializes a new instance of a  class.
        /// 
        public HtmlInputCheckBox() : base("checkbox") { 
        }
 
        /* 
         * Checked property.
         */ 

        /// 
        ///    Gets or sets a value indicating whether the checkbox is
        ///       currently selected. 
        /// 
        [ 
        WebCategory("Default"), 
        DefaultValue(""),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        TypeConverter(typeof(MinimizableAttributeTypeConverter))
        ]
        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;
            } 
        }
 
        /* 
        * Adds an event handler for the OnServerChange event.
        *  value: New handler to install for this event. 
        */

        /// 
        ///    Occurs when  
        /// 
        [ 
        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 unless
            // we are disabled 
            if (Events[EventServerChange] == null && !Disabled) {
                ViewState.SetItemDirty("checked",false);
            }
        } 

        /* 
         * Method used to raise the OnServerChange event. 
         */
 
        /// 
        ///    [To be supplied.]
        /// 
        protected virtual void OnServerChange(EventArgs e) { 
            // invoke delegates AFTER binding
            EventHandler handler = (EventHandler)Events[EventServerChange]; 
            if (handler != null) handler(this, e); 
        }
 
        /*
         * Method of IPostBackDataHandler interface to process posted data.
         * Checkbox determines the posted Checked state.
         */ 

        ///  
        bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection) { 
            return LoadPostData(postDataKey, postCollection);
        } 


        /// 
        protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection) { 
            string post = postCollection[postDataKey];
            bool newValue = !String.IsNullOrEmpty(post); 
            bool valueChanged = (newValue != Checked); 
            Checked = newValue;
 
            if (newValue) {
                ValidateEvent(postDataKey);
            }
 
            return valueChanged;
        } 
 
        protected override void RenderAttributes(HtmlTextWriter writer) {
            base.RenderAttributes(writer); 

            if (Page != null) {
                Page.ClientScript.RegisterForEventValidation(RenderedNameAttribute);
            } 
        }
 
        /* 
         [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
         [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
         * 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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