CheckBoxList.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / WebControls / CheckBoxList.cs / 1477082 / CheckBoxList.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.Collections; 
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.Globalization;
    using System.Web; 
    using System.Web.UI;
    using System.Web.Util; 
 
    /// 
    /// Creates a group of  controls. 
    /// 
    public class CheckBoxList : ListControl, IRepeatInfoUser, INamingContainer, IPostBackDataHandler {
        private CheckBox _controlToRepeat;
        private string _oldAccessKey; 
        private bool _hasNotifiedOfChange;
        private bool _cachedRegisterEnabled; 
        private bool _cachedIsEnabled; 

        ///  
        ///    
        ///       Initializes a new instance of the  class.
        ///    
        ///  
        public CheckBoxList() {
            _controlToRepeat = new CheckBox(); 
            _controlToRepeat.EnableViewState = false; 

            // Whidbey 28457: We need to set a default numeric ID for the case 
            // of an empty checkbox list.  It is because the child CheckBox
            // always registers itself to Page as a PostBackData control and
            // during postback it will invoke LoadPostData in this class and the
            // method always assumes the ID is numeric.  This default ID setting 
            // has been done in this way since V1.
            _controlToRepeat.ID = "0"; 
 
            Controls.Add(_controlToRepeat);
        } 


        /// 
        ///     
        ///       Gets or sets
        ///       the padding between each item. 
        ///     
        /// 
        [ 
        WebCategory("Layout"),
        DefaultValue(-1),
        WebSysDescription(SR.CheckBoxList_CellPadding)
        ] 
        public virtual int CellPadding {
            get { 
                if (ControlStyleCreated == false) { 
                    return -1;
                } 
                return ((TableStyle)ControlStyle).CellPadding;
            }
            set {
                ((TableStyle)ControlStyle).CellPadding = value; 
            }
        } 
 

        ///  
        ///    
        ///       Gets or sets
        ///       the spacing between each item.
        ///     
        /// 
        [ 
        WebCategory("Layout"), 
        DefaultValue(-1),
        WebSysDescription(SR.CheckBoxList_CellSpacing) 
        ]
        public virtual int CellSpacing {
            get {
                if (ControlStyleCreated == false) { 
                    return -1;
                } 
                return ((TableStyle)ControlStyle).CellSpacing; 
            }
            set { 
                ((TableStyle)ControlStyle).CellSpacing = value;
            }
        }
 
        internal override bool IsMultiSelectInternal  {
            get  { 
                // a CheckBoxList is always multiselect. 
                return true;
            } 
        }


        ///  
        ///    Gets or sets the number of columns to repeat.
        ///  
        [ 
        WebCategory("Layout"),
        DefaultValue(0), 
        WebSysDescription(SR.CheckBoxList_RepeatColumns)
        ]
        public virtual int RepeatColumns {
            get { 
                object o = ViewState["RepeatColumns"];
                return((o == null) ? 0 : (int)o); 
            } 
            set {
                if (value < 0) { 
                    throw new ArgumentOutOfRangeException("value");
                }
                ViewState["RepeatColumns"] = value;
            } 
        }
 
 
        /// 
        ///    Gets or sets a value that indicates whether the control is displayed 
        ///       vertically or horizontally.
        /// 
        [
        WebCategory("Layout"), 
        DefaultValue(RepeatDirection.Vertical),
        WebSysDescription(SR.Item_RepeatDirection) 
        ] 
        public virtual RepeatDirection RepeatDirection {
            get { 
                object o = ViewState["RepeatDirection"];
                return((o == null) ? RepeatDirection.Vertical : (RepeatDirection)o);
            }
            set { 
                if (value < RepeatDirection.Horizontal || value > RepeatDirection.Vertical) {
                    throw new ArgumentOutOfRangeException("value"); 
                } 
                ViewState["RepeatDirection"] = value;
            } 
        }


        ///  
        ///    Gets or sets a value that indicates whether the control is displayed in
        ///    or layout. 
        ///  
        [
        WebCategory("Layout"), 
        DefaultValue(RepeatLayout.Table),
        WebSysDescription(SR.WebControl_RepeatLayout)
        ]
        public virtual RepeatLayout RepeatLayout { 
            get {
                object o = ViewState["RepeatLayout"]; 
                return((o == null) ? RepeatLayout.Table : (RepeatLayout)o); 
            }
            set { 
                EnumerationRangeValidationUtil.ValidateRepeatLayout(value);
                ViewState["RepeatLayout"] = value;
            }
        } 

 
        ///  
        ///    Gets or sets
        ///       the alignment of the text label associated with each checkbox. 
        /// 
        [
        WebCategory("Appearance"),
        DefaultValue(TextAlign.Right), 
        WebSysDescription(SR.WebControl_TextAlign)
        ] 
        public virtual TextAlign TextAlign { 
            get {
                object align = ViewState["TextAlign"]; 
                return((align == null) ? TextAlign.Right : (TextAlign)align);
            }
            set {
                if (value < TextAlign.Left || value > TextAlign.Right) { 
                    throw new ArgumentOutOfRangeException("value");
                } 
                ViewState["TextAlign"] = value; 
            }
        } 


        /// 
        ///  
        ///    Creates a new control style object.
        ///  
        protected override Style CreateControlStyle() { 
            return new TableStyle(ViewState);
        } 


        /// 
        ///  
        /// Catches post data for each  in the list.
        ///  
        protected override Control FindControl(string id, int pathOffset) { 
            return this;
        } 

        /// 
        /// 
        /// Configures the  prior to rendering on the client. 
        /// 
        protected internal override void OnPreRender(EventArgs e) { 
            base.OnPreRender(e); 
            _controlToRepeat.AutoPostBack = AutoPostBack;
            _controlToRepeat.CausesValidation = CausesValidation; 
            _controlToRepeat.ValidationGroup = ValidationGroup;

            if (Page != null) {
                // ensure postback data for those checkboxes which get unchecked or are different from their default value 
                for (int i=0; i < Items.Count; i++) {
                    SetControlToRepeatID(this, _controlToRepeat, i); 
                    Page.RegisterRequiresPostBack(_controlToRepeat); 
                }
            } 
        }


        ///  
        /// 
        ///     
        ///       Displays the  on the client. 
        ///    
        ///  
        protected internal override void Render(HtmlTextWriter writer) {
            // Don't render anything if the control is empty.
            // empty table is not xhtml compliant.
            if (Items.Count == 0 && !EnableLegacyRendering) { 
                return;
            } 
 
            RepeatInfo repeatInfo = new RepeatInfo();
            Style style = (ControlStyleCreated ? ControlStyle : null); 
            short tabIndex = TabIndex;
            bool undirtyTabIndex = false;

            // TabIndex here is special... it needs to be applied to the individual 
            // checkboxes and not the outer control itself
 
            // Set the TextAlign property. 
            _controlToRepeat.TextAlign = TextAlign;
 
            // cache away the TabIndex property state
            _controlToRepeat.TabIndex = tabIndex;
            if (tabIndex != 0) {
                if (ViewState.IsItemDirty("TabIndex") == false) { 
                    undirtyTabIndex = true;
                } 
                TabIndex = 0; 
            }
 
            repeatInfo.RepeatColumns = RepeatColumns;
            repeatInfo.RepeatDirection = RepeatDirection;

            // If the device does not support tables, use the flow layout to render 
            if (!DesignMode && !Context.Request.Browser.Tables) {
                repeatInfo.RepeatLayout = RepeatLayout.Flow; 
            } 
            else {
                repeatInfo.RepeatLayout = RepeatLayout; 
            }

            if (repeatInfo.RepeatLayout == RepeatLayout.Flow) {
                repeatInfo.EnableLegacyRendering = EnableLegacyRendering; 
            }
 
            // VSWhidbey 373655 
            // Temporarily suppress AccessKey so base does not render it on the outside tag
            _oldAccessKey = AccessKey; 
            AccessKey = String.Empty;

            repeatInfo.RenderRepeater(writer, (IRepeatInfoUser)this, style, this);
 
            // restore the state of AccessKey property
            AccessKey = _oldAccessKey; 
 
            // restore the state of the TabIndex property
            if (tabIndex != 0) { 
                TabIndex = tabIndex;
            }
            if (undirtyTabIndex) {
                ViewState.SetItemDirty("TabIndex", false); 
            }
        } 
 
        /// 
        ///  
        /// Processes posted data for the  control.
        /// 
        bool IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) {
            return LoadPostData(postDataKey, postCollection); 
        }
 
 
        /// 
        ///  
        /// Processes posted data for the  control.
        /// 
        protected virtual bool LoadPostData(String postDataKey, NameValueCollection postCollection) {
            if (IsEnabled == false) { 
                // When a CheckBoxList is disabled, then there is no postback
                // data for it. Any checked state information has been loaded 
                // via view state. 
                return false;
            } 

            // postDataKey looks like one of two things:
            // 1. "$" (EffectiveClientIDMode != Static when rendered last request)
            // 2. "$_" (EffectiveClientIDMode == Static last request) 

            string strIndex = postDataKey.Substring(UniqueID.Length + 1); 
            // strIndex is now either (1) "" or (2) "_" 
            // Detect case #2 by looking for an underscore. Use LastIndexOf in case  contains one too.
            // No need to worry about a case that looks like "$", it would never have been rendered that way. 
            int underscoreIndex = strIndex.LastIndexOf('_');
            if (underscoreIndex != -1) {
                strIndex = strIndex.Substring(underscoreIndex + 1);
            } 
            // strIndex is now definitely the index as a string, regardless of which case postDataKey was in.
            int index = Int32.Parse(strIndex, CultureInfo.InvariantCulture); 
 
            EnsureDataBound();
 
            // Maintain state from the form
            if (index >= 0 && index < Items.Count) {
                ListItem item = Items[index];
                if (item.Enabled == false) { 
                    return false;
                } 
 
                bool newCheckState = (postCollection[postDataKey] != null);
 
                if (item.Selected != newCheckState) {
                    item.Selected = newCheckState;
                    // LoadPostData will be invoked for each CheckBox that changed
                    // Suppress multiple change notification and fire only ONE change event 
                    if (!_hasNotifiedOfChange) {
                        _hasNotifiedOfChange = true; 
                        return true; 
                    }
                } 
            }

            return false;
        } 

 
        ///  
        /// 
        /// Raises when posted data for a control has changed. 
        /// 
        void IPostBackDataHandler.RaisePostDataChangedEvent() {
            RaisePostDataChangedEvent();
        } 

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

        ///  
        ///  
        /// 
        bool IRepeatInfoUser.HasFooter { 
            get {
                return HasFooter;
            }
        } 

 
        ///  
        /// 
        ///  
        protected virtual bool HasFooter {
            get {
                return false;
            } 
        }
 
 
        /// 
        ///  
        /// 
        bool IRepeatInfoUser.HasHeader {
            get {
                return HasHeader; 
            }
        } 
 

        ///  
        /// 
        /// 
        protected virtual bool HasHeader {
            get { 
                return false;
            } 
        } 

 
        /// 
        /// 
        /// 
        bool IRepeatInfoUser.HasSeparators { 
            get {
                return HasSeparators; 
            } 
        }
 

        /// 
        /// 
        ///  
        protected virtual bool HasSeparators {
            get { 
                return false; 
            }
        } 


        /// 
        ///  
        /// 
        int IRepeatInfoUser.RepeatedItemCount { 
            get { 
                return RepeatedItemCount;
            } 
        }


        ///  
        /// 
        ///  
        protected virtual int RepeatedItemCount { 
            get {
                return (Items != null) ? Items.Count : 0; 
            }
        }

 
        /// 
        ///  
        ///  
        Style IRepeatInfoUser.GetItemStyle(ListItemType itemType, int repeatIndex) {
            return GetItemStyle(itemType, repeatIndex); 
        }


        protected virtual Style GetItemStyle(ListItemType itemType, int repeatIndex) { 
            return null;
        } 
 

        ///  
        /// 
        /// Called by the RepeatInfo helper to render each item
        /// 
        void IRepeatInfoUser.RenderItem(ListItemType itemType, int repeatIndex, RepeatInfo repeatInfo, HtmlTextWriter writer) { 
            RenderItem(itemType, repeatIndex, repeatInfo, writer);
        } 
 

        ///  
        /// 
        /// Called by the RepeatInfo helper to render each item
        /// 
        protected virtual void RenderItem(ListItemType itemType, int repeatIndex, RepeatInfo repeatInfo, HtmlTextWriter writer) { 
            if (repeatIndex == 0) {
                _cachedIsEnabled = IsEnabled; 
                _cachedRegisterEnabled = (Page != null) && IsEnabled && (SaveSelectedIndicesViewState == false); 
            }
 
            int repeatIndexOffset = repeatIndex;

            ListItem item = Items[repeatIndexOffset];
 
            // VSWhidbey 403433 Render expando attributes.
            _controlToRepeat.Attributes.Clear(); 
            if (item.HasAttributes) { 
                foreach (string key in item.Attributes.Keys) {
                    _controlToRepeat.Attributes[key] = item.Attributes[key]; 
                }
            }

            // Dev10 684108: reset the CssClass for each item. 
            if (!string.IsNullOrEmpty(_controlToRepeat.CssClass)) {
                _controlToRepeat.CssClass = ""; 
            } 

            if (RenderingCompatibility >= VersionUtil.Framework40) { 
                _controlToRepeat.InputAttributes.Add("value", item.Value);
            }
            SetControlToRepeatID(this, _controlToRepeat, repeatIndexOffset);
            _controlToRepeat.Text = item.Text; 
            _controlToRepeat.Checked = item.Selected;
            _controlToRepeat.Enabled = _cachedIsEnabled && item.Enabled; 
            _controlToRepeat.AccessKey = _oldAccessKey; 

            if (_cachedRegisterEnabled && _controlToRepeat.Enabled) { 
                // Store a client-side array of enabled control, so we can re-enable them on
                // postback (in case they are disabled client-side)
                // Postback is needed when SelectedIndices is not saved in view state
                Page.RegisterEnabledControl(_controlToRepeat); 
            }
 
            _controlToRepeat.RenderControl(writer); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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CheckBoxList.cs source code in C# .NET

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