RadioButton.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 / WebControls / RadioButton.cs / 1 / RadioButton.cs
                        

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

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

    ///  
    ///    Constructs a radio button and defines its
    ///       properties.
    /// 
    [ 
    Designer("System.Web.UI.Design.WebControls.CheckBoxDesigner, " + AssemblyRef.SystemDesign),
    SupportsEventValidation, 
    ] 
    [AspNetHostingPermission(SecurityAction.LinkDemand, Level=AspNetHostingPermissionLevel.Minimal)]
    [AspNetHostingPermission(SecurityAction.InheritanceDemand, Level=AspNetHostingPermissionLevel.Minimal)] 
    public class RadioButton : CheckBox, IPostBackDataHandler {

#if SHIPPINGADAPTERS
        internal static readonly string AltSelectedText = "(o)"; 
        internal static readonly string AltUnselectedText = "(_)";
#endif 
 
        private string _uniqueGroupName = null;
 

        /// 
        /// Initializes a new instance of the  class.
        ///  
        public RadioButton() {
        } 
 

        ///  
        ///    Gets or
        ///       sets the name of the group that the radio button belongs to.
        /// 
        [ 
        DefaultValue(""),
        WebCategory("Behavior"), 
        WebSysDescription(SR.RadioButton_GroupName), 
        Themeable(false),
        ] 
        public virtual string GroupName {
            get {
                string s = (string)ViewState["GroupName"];
                return((s == null) ? String.Empty : s); 
            }
            set { 
                ViewState["GroupName"] = value; 
            }
        } 

        // Fully qualified GroupName for rendering purposes, to take care of conflicts
        // between different naming containers
        internal string UniqueGroupName { 
            get {
                if (_uniqueGroupName == null) { 
                    // For radio buttons, we must make the groupname 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 = GroupName;
                    string uid = UniqueID;

                    if (uid != null) { 
                        int lastColon = uid.LastIndexOf(IdSeparator);
                        if (lastColon >= 0) { 
                            if (name.Length > 0) { 
                                name = uid.Substring(0, lastColon+1) + name;
                            } 
                            else if (NamingContainer is RadioButtonList) {
                                // If GroupName is not set we simply use the naming
                                // container as the group name
                                name = uid.Substring(0, lastColon); 
                            }
                        } 
 
                        if (name.Length == 0) {
                            name = uid; 
                        }
                    }

                    _uniqueGroupName = name; 
                }
                return _uniqueGroupName; 
            } 
        }
 

        /// 
        /// 
        internal string ValueAttribute { 
            get {
                string valueAttr = Attributes["value"]; 
                if (valueAttr == null) { 

                    // VSWhidbey 146829. Always EnsureID so the valueAttribute will not change by 
                    // call to ClientID which happens during Render.
                    EnsureID();

                    if (ID != null) 
                        valueAttr = ID;
                    else 
                        valueAttr = UniqueID; 
                }
 
                return valueAttr;
            }
        }
 

        ///  
        ///  
        ///    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);
        } 

 
        ///  
        /// 
        ///    Method of IPostBackDataHandler interface to process posted data. 
        ///       RadioButton determines the posted radio group state.
        /// 
        protected override bool LoadPostData(String postDataKey, NameValueCollection postCollection) {
            string post = postCollection[UniqueGroupName]; 
            bool valueChanged = false;
            if ((post != null) && post.Equals(ValueAttribute)) { 
 
                ValidateEvent(UniqueGroupName, post);
 
                if (Checked == false) {
                    Checked = true;
                    // only fire change event for RadioButton that is being checked
                    valueChanged = true; 
                }
            } 
            else { 
                if (Checked == true) {
                    Checked = false; 
                }
            }

            return valueChanged; 
        }
 
 
        /// 
        ///  
        /// Raises when posted data for a control has changed.
        /// 
        void IPostBackDataHandler.RaisePostDataChangedEvent() {
            RaisePostDataChangedEvent(); 
        }
 
 
        /// 
        ///  
        /// Raises when posted data for a control has changed.
        /// 
        protected override void RaisePostDataChangedEvent() {
            if (AutoPostBack && !Page.IsPostBackEventControlRegistered) { 
                // VSWhidbey 204824
                Page.AutoPostBackControl = this; 
 
                if (CausesValidation) {
                    Page.Validate(ValidationGroup); 
                }
            }
            OnCheckedChanged(EventArgs.Empty);
        } 

 
        ///  
        /// 
        ///    This method is invoked just prior to rendering. 
        ///    Register client script for handling postback if onChangeHandler is set.
        /// 
        protected internal override void OnPreRender(EventArgs e) {
            // must call CheckBox PreRender 
            base.OnPreRender(e);
 
            if (Page != null && !Checked && Enabled) { 
                Page.RegisterRequiresPostBack(this);
            } 
        }

        internal override void RenderInputTag(HtmlTextWriter writer, string clientID, string onClick) {
 
            writer.AddAttribute(HtmlTextWriterAttribute.Id, clientID);
            writer.AddAttribute(HtmlTextWriterAttribute.Type, "radio"); 
            writer.AddAttribute(HtmlTextWriterAttribute.Name, UniqueGroupName); 
            writer.AddAttribute(HtmlTextWriterAttribute.Value, ValueAttribute);
 
            if (Page != null) {
                Page.ClientScript.RegisterForEventValidation(UniqueGroupName, ValueAttribute);
            }
 
            if (Checked)
                writer.AddAttribute(HtmlTextWriterAttribute.Checked, "checked"); 
 
            // ASURT 119141: Render Disabled attribute on the INPUT tag (instead of the SPAN) so the checkbox actually gets disabled when Enabled=false
            if (!IsEnabled) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled");
            }

            // We don't do autopostback if the radio button has been selected. 
            // This is to make it consistent that it only posts back if its
            // state has been changed.  Also, it avoids the problem of missing 
            // validation since the data changed event would not be fired if the 
            // selected radio button was posting back.
            if (AutoPostBack && !Checked && Page != null) { 

                PostBackOptions options = new PostBackOptions(this, String.Empty);

                // ASURT 98368 
                // Need to merge the autopostback script with the user script
                if (CausesValidation) { 
                    options.PerformValidation = true; 
                    options.ValidationGroup = ValidationGroup;
                } 

                if (Page.Form != null) {
                    options.AutoPostBack = true;
                } 

                onClick = Util.MergeScript(onClick, Page.ClientScript.GetPostBackEventReference(options)); 
                writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick); 
                if (EnableLegacyRendering) {
                    writer.AddAttribute("language", "javascript", false); 
                }
            }
            else {
                if (onClick != null) { 
                    writer.AddAttribute(HtmlTextWriterAttribute.Onclick, onClick);
                } 
            } 

            string s = AccessKey; 
            if (s.Length > 0)
                writer.AddAttribute(HtmlTextWriterAttribute.Accesskey, s);

            int i = TabIndex; 
            if (i != 0) {
                writer.AddAttribute(HtmlTextWriterAttribute.Tabindex, i.ToString(NumberFormatInfo.InvariantInfo)); 
            } 

            if (_inputAttributes != null && _inputAttributes.Count != 0) { 
                _inputAttributes.AddAttributes(writer);
            }

            writer.RenderBeginTag(HtmlTextWriterTag.Input); 
            writer.RenderEndTag();
        } 
    } 
}

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