RadioButton.cs source code in C# .NET

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/ DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / System / Windows / Controls / RadioButton.cs / 1 / RadioButton.cs

                            using System; 
using System.Collections;
using System.ComponentModel;
using System.Threading;
using System.Windows.Threading; 

using System.Windows.Automation; 
using System.Windows.Controls.Primitives; 
using System.Windows.Data;
using System.Windows; 
using System.Windows.Input;
using System.Windows.Media;
using MS.Utility;
 
// Disable CS3001: Warning as Error: not CLS-compliant
#pragma warning disable 3001 
 
namespace System.Windows.Controls
{ 
    /// 
    ///     RadioButton implements option button with two states: true or false
    /// 
    [Localizability(LocalizationCategory.RadioButton)] 
    public class RadioButton : ToggleButton
    { 
        #region Constructors 

        static RadioButton() 
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(RadioButton), new FrameworkPropertyMetadata(typeof(RadioButton)));
            _dType = DependencyObjectType.FromSystemTypeInternal(typeof(RadioButton));
 
            KeyboardNavigation.AcceptsReturnProperty.OverrideMetadata(typeof(RadioButton), new FrameworkPropertyMetadata(MS.Internal.KnownBoxes.BooleanBoxes.FalseBox));
        } 
 
        /// 
        ///     Default RadioButton constructor 
        /// 
        /// 
        ///     Automatic determination of current Dispatcher. Use alternative constructor
        ///     that accepts a Dispatcher for best performance. 
        /// 
        public RadioButton() : base() 
        { 
        }
 
        #endregion

        #region private helpers
 
        private static void OnGroupNameChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        { 
            RadioButton radioButton = (RadioButton)d; 
            string groupName = e.NewValue as string;
            string currentlyRegisteredGroupName = _currentlyRegisteredGroupName.GetValue(radioButton); 

            if (groupName != currentlyRegisteredGroupName)
            {
                // Unregister the old group name if set 
                if (!string.IsNullOrEmpty(currentlyRegisteredGroupName))
                    Unregister(currentlyRegisteredGroupName, radioButton); 
 
                // Register the new group name is set
                if (!string.IsNullOrEmpty(groupName)) 
                    Register(groupName, radioButton);
            }
        }
 
        private static void Register(string groupName, RadioButton radioButton)
        { 
            if (_groupNameToElements == null) 
                _groupNameToElements = new Hashtable(1);
 
            lock (_groupNameToElements)
            {
                ArrayList elements = (ArrayList)_groupNameToElements[groupName];
 
                if (elements == null)
                { 
                    elements = new ArrayList(1); 
                    _groupNameToElements[groupName] = elements;
                } 
                else
                {
                    // There were some elements there, remove dead ones
                    PurgeDead(elements, null); 
                }
 
                elements.Add(new WeakReference(radioButton)); 
            }
            _currentlyRegisteredGroupName.SetValue(radioButton, groupName); 
        }

        private static void Unregister(string groupName, RadioButton radioButton)
        { 
            if (_groupNameToElements == null)
                return; 
 
            lock (_groupNameToElements)
            { 
                // Get all elements bound to this key and remove this element
                ArrayList elements = (ArrayList)_groupNameToElements[groupName];

                if (elements != null) 
                {
                    PurgeDead(elements, radioButton); 
                    if (elements.Count == 0) 
                    {
                        _groupNameToElements.Remove(groupName); 
                    }
                }
            }
            _currentlyRegisteredGroupName.SetValue(radioButton, null); 
        }
 
        private static void PurgeDead(ArrayList elements, object elementToRemove) 
        {
            for (int i = 0; i < elements.Count; ) 
            {
                WeakReference weakReference = (WeakReference)elements[i];
                object element = weakReference.Target;
                if (element == null || element == elementToRemove) 
                {
                    elements.RemoveAt(i); 
                } 
                else
                { 
                    i++;
                }
            }
        } 

        private void UpdateRadioButtonGroup() 
        { 
            string groupName = GroupName;
            if (!string.IsNullOrEmpty(groupName)) 
            {
                Visual rootScope = KeyboardNavigation.GetVisualRoot(this);
                if (_groupNameToElements == null)
                    _groupNameToElements = new Hashtable(1); 
                lock (_groupNameToElements)
                { 
                    // Get all elements bound to this key and remove this element 
                    ArrayList elements = (ArrayList)_groupNameToElements[groupName];
                    for (int i = 0; i < elements.Count; ) 
                    {
                        WeakReference weakReference = (WeakReference)elements[i];
                        RadioButton rb = weakReference.Target as RadioButton;
                        if (rb == null) 
                        {
                            // Remove dead instances 
                            elements.RemoveAt(i); 
                        }
                        else 
                        {
                            // Uncheck all checked RadioButtons different from the current one
                            if (rb != this && (rb.IsChecked == true) && rootScope == KeyboardNavigation.GetVisualRoot(rb))
                                rb.UncheckRadioButton(); 
                            i++;
                        } 
                    } 
                }
            } 
            else // Logical parent should be the group
            {
                DependencyObject parent = this.Parent;
                if (parent != null) 
                {
                    // Traverse logical children 
                    IEnumerable children = LogicalTreeHelper.GetChildren(parent); 
                    IEnumerator itor = children.GetEnumerator();
                    while (itor.MoveNext()) 
                    {
                        RadioButton rb = itor.Current as RadioButton;
                        if (rb != null && rb != this && string.IsNullOrEmpty(rb.GroupName) && (rb.IsChecked == true))
                            rb.UncheckRadioButton(); 
                    }
                } 
 
            }
        } 

        private void UncheckRadioButton()
        {
            ClearValue(IsCheckedProperty); 
            // If IsChecked is still true and the value source is not a trigger - set local value to false
            if (IsChecked == true) 
            { 
                bool hasModifiers;
                BaseValueSourceInternal valueSource = GetValueSource(IsCheckedProperty, null, out hasModifiers); 
                if (valueSource != BaseValueSourceInternal.ThemeStyleTrigger &&
                    valueSource != BaseValueSourceInternal.TemplateTrigger &&
                    valueSource != BaseValueSourceInternal.ParentTemplateTrigger)
                { 
                    IsChecked = false;
                } 
            } 
        }
 
        #endregion

        #region Properties and Events
 
        /// 
        /// The DependencyID for the GroupName property. 
        /// Default Value:      "String.Empty" 
        /// 
        public static readonly DependencyProperty GroupNameProperty = DependencyProperty.Register( 
            "GroupName",
            typeof(string),
            typeof(RadioButton),
            new FrameworkPropertyMetadata(String.Empty, new PropertyChangedCallback(OnGroupNameChanged))); 

        ///  
        /// GroupName determine mutually excusive radiobutton groups 
        /// 
        [DefaultValue("")] 
        [Localizability(LocalizationCategory.NeverLocalize)] // cannot be localized
        public string GroupName
        {
            get 
            {
                return (string)GetValue(GroupNameProperty); 
            } 

            set 
            {
                SetValue(GroupNameProperty, value);
            }
        } 

        #endregion 
 
        #region Override methods
 
        /// 
        /// Creates AutomationPeer ()
        /// 
        protected override System.Windows.Automation.Peers.AutomationPeer OnCreateAutomationPeer() 
        {
            return new System.Windows.Automation.Peers.RadioButtonAutomationPeer(this); 
        } 

        ///  
        ///     This method is invoked when the IsChecked becomes true.
        /// 
        /// RoutedEventArgs.
        protected override void OnChecked(RoutedEventArgs e) 
        {
            // If RadioButton is checked we should uncheck the others in the same group 
            UpdateRadioButtonGroup(); 
            base.OnChecked(e);
        } 

        /// 
        /// This override method is called from OnClick().
        /// RadioButton implements its own toggle behavior 
        /// 
        protected internal override void OnToggle() 
        { 
            IsChecked = true;
        } 

        /// 
        /// The Access key for this control was invoked.
        ///  
        /// 
        protected override void OnAccessKey(AccessKeyEventArgs e) 
        { 
            if (!IsKeyboardFocused)
            { 
                Focus();
            }

            base.OnAccessKey(e); 
        }
 
 
        #endregion
 
        #region Accessibility

        #endregion Accessibility
 
        #region DTypeThemeStyleKey
 
        // Returns the DependencyObjectType for the registered ThemeStyleKey's default 
        // value. Controls will override this method to return approriate types.
        internal override DependencyObjectType DTypeThemeStyleKey 
        {
            get { return _dType; }
        }
 
        private static DependencyObjectType _dType;
 
        #endregion DTypeThemeStyleKey 

        #region private data 

        [ThreadStatic] private static Hashtable _groupNameToElements;
        private static readonly UncommonField _currentlyRegisteredGroupName = new UncommonField();
 
        #endregion private data
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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