HtmlInputCheckBox.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / HtmlControls / HtmlInputCheckBox.cs / 1305376 / 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, 
    ]
    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);
            }
        }
 
        /*
         * 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);
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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