Listbox.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / Web / UI / WebControls / Listbox.cs / 1305376 / Listbox.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.Drawing;
    using System.Globalization; 
    using System.Web;
    using System.Web.UI; 
 
    /// 
    ///    Constructs a list box and defines its 
    ///       properties.
    /// 
    [
    ValidationProperty("SelectedItem"), 
    SupportsEventValidation
    ] 
    public class ListBox : ListControl, IPostBackDataHandler { 

 
        /// 
        /// Initializes a new instance of the  class.
        /// 
        public ListBox() { 
        }
 
 
        /// 
        ///    [To be supplied.] 
        /// 
        [
        Browsable(false)
        ] 
        public override Color BorderColor {
            get { 
                return base.BorderColor; 
            }
            set { 
                base.BorderColor = value;
            }
        }
 

        ///  
        ///    [To be supplied.] 
        /// 
        [ 
        Browsable(false)
        ]
        public override BorderStyle BorderStyle {
            get { 
                return base.BorderStyle;
            } 
            set { 
                base.BorderStyle = value;
            } 
        }


        ///  
        ///    [To be supplied.]
        ///  
        [ 
        Browsable(false)
        ] 
        public override Unit BorderWidth {
            get {
                return base.BorderWidth;
            } 
            set {
                base.BorderWidth = value; 
            } 
        }
 
        internal override bool IsMultiSelectInternal  {
            get  {
                return SelectionMode == ListSelectionMode.Multiple;
            } 
        }
 
 
        /// 
        ///     Gets or 
        ///       sets the display height (in rows) of the list box.
        /// 
        [
        WebCategory("Appearance"), 
        DefaultValue(4),
        WebSysDescription(SR.ListBox_Rows) 
        ] 
        public virtual int Rows {
            get { 
                object n = ViewState["Rows"];
                return((n == null) ? 4 : (int)n);
            }
            set { 
                if (value < 1) {
                    throw new ArgumentOutOfRangeException("value"); 
                } 
                ViewState["Rows"] = value;
            } 
        }


        ///  
        ///    Gets or sets
        ///       the selection behavior of the list box. 
        ///  
        [
        WebCategory("Behavior"), 
        DefaultValue(ListSelectionMode.Single),
        WebSysDescription(SR.ListBox_SelectionMode)
        ]
        public virtual ListSelectionMode SelectionMode { 
            get {
                object sm = ViewState["SelectionMode"]; 
                return((sm == null) ? ListSelectionMode.Single : (ListSelectionMode)sm); 
            }
            set { 
                if (value < ListSelectionMode.Single || value > ListSelectionMode.Multiple) {
                    throw new ArgumentOutOfRangeException("value");
                }
                ViewState["SelectionMode"] = value; 
            }
        } 
 

        ///  
        protected override void AddAttributesToRender(HtmlTextWriter writer) {
            writer.AddAttribute(HtmlTextWriterAttribute.Size,
                                        Rows.ToString(NumberFormatInfo.InvariantInfo));
 
            string uniqueID = UniqueID;
            if (uniqueID != null) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID); 
            }
 
            base.AddAttributesToRender(writer);
        }

 
        public virtual int[] GetSelectedIndices() {
            return (int[])SelectedIndicesInternal.ToArray(typeof(int)); 
        } 

 
        /// 
        /// 
        /// 
        protected internal override void OnPreRender(EventArgs e) { 
            base.OnPreRender(e);
            if (Page != null && SelectionMode == ListSelectionMode.Multiple && Enabled) { 
 
                // ensure postback when no item is selected
                Page.RegisterRequiresPostBack(this); 
            }
        }

 
        /// 
        ///  
        /// Loads the posted content of the list control if it is different from the last 
        /// posting.
        ///  
        bool IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) {
            return LoadPostData(postDataKey, postCollection);
        }
 

        ///  
        ///  
        /// Loads the posted content of the list control if it is different from the last
        /// posting. 
        /// 
        protected virtual bool LoadPostData(String postDataKey, NameValueCollection postCollection) {
            if (IsEnabled == false) {
                // When a ListBox is disabled, then there is no postback 
                // data for it. Any checked state information has been loaded
                // via view state. 
                return false; 
            }
 
            string[] selectedItems = postCollection.GetValues(postDataKey);
            bool selectionChanged = false;

            EnsureDataBound(); 
            if (selectedItems != null) {
                if (SelectionMode == ListSelectionMode.Single) { 
 
                    ValidateEvent(postDataKey, selectedItems[0]);
 
                    int n = Items.FindByValueInternal(selectedItems[0], false);
                    if (SelectedIndex != n) {
                        SetPostDataSelection(n);
                        selectionChanged = true; 
                    }
                } 
                else { // multiple selection 
                    int count = selectedItems.Length;
                    ArrayList oldSelectedIndices = SelectedIndicesInternal; 
                    ArrayList newSelectedIndices = new ArrayList(count);
                    for (int i=0; i < count; i++) {

                        ValidateEvent(postDataKey, selectedItems[i]); 

                        // create array of new indices from posted values 
                        newSelectedIndices.Add(Items.FindByValueInternal(selectedItems[i], false)); 
                    }
 
                    int oldcount = 0;
                    if (oldSelectedIndices != null)
                        oldcount = oldSelectedIndices.Count;
 
                    if (oldcount == count) {
                        // check new indices against old indices 
                        // assumes selected values are posted in order 
                        for (int i=0; i < count; i++) {
                            if (((int)newSelectedIndices[i]) != ((int)oldSelectedIndices[i])) { 
                                selectionChanged = true;
                                break;
                            }
                        } 
                    }
                    else { 
                        // indices must have changed if count is different 
                        selectionChanged = true;
                    } 

                    if (selectionChanged) {
                        // select new indices
                        SelectInternal(newSelectedIndices); 
                    }
                } 
            } 
            else { // no items selected
                if (SelectedIndex != -1) { 
                    SetPostDataSelection(-1);
                    selectionChanged = true;
                }
            } 

            return selectionChanged; 
        } 

 
        /// 
        /// 
        /// Invokes the OnSelectedIndexChanged method whenever posted data
        /// for the  control has changed. 
        /// 
        void IPostBackDataHandler.RaisePostDataChangedEvent() { 
            RaisePostDataChangedEvent(); 
        }
 

        /// 
        /// 
        /// Invokes the OnSelectedIndexChanged method whenever posted data 
        /// for the  control has changed.
        ///  
        protected virtual void RaisePostDataChangedEvent() { 
            if (AutoPostBack && !Page.IsPostBackEventControlRegistered) {
                // VSWhidbey 204824 
                Page.AutoPostBackControl = this;

                if (CausesValidation) {
                    Page.Validate(ValidationGroup); 
                }
            } 
            OnSelectedIndexChanged(EventArgs.Empty); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//------------------------------------------------------------------------------ 
// 
//     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.Drawing;
    using System.Globalization; 
    using System.Web;
    using System.Web.UI; 
 
    /// 
    ///    Constructs a list box and defines its 
    ///       properties.
    /// 
    [
    ValidationProperty("SelectedItem"), 
    SupportsEventValidation
    ] 
    public class ListBox : ListControl, IPostBackDataHandler { 

 
        /// 
        /// Initializes a new instance of the  class.
        /// 
        public ListBox() { 
        }
 
 
        /// 
        ///    [To be supplied.] 
        /// 
        [
        Browsable(false)
        ] 
        public override Color BorderColor {
            get { 
                return base.BorderColor; 
            }
            set { 
                base.BorderColor = value;
            }
        }
 

        ///  
        ///    [To be supplied.] 
        /// 
        [ 
        Browsable(false)
        ]
        public override BorderStyle BorderStyle {
            get { 
                return base.BorderStyle;
            } 
            set { 
                base.BorderStyle = value;
            } 
        }


        ///  
        ///    [To be supplied.]
        ///  
        [ 
        Browsable(false)
        ] 
        public override Unit BorderWidth {
            get {
                return base.BorderWidth;
            } 
            set {
                base.BorderWidth = value; 
            } 
        }
 
        internal override bool IsMultiSelectInternal  {
            get  {
                return SelectionMode == ListSelectionMode.Multiple;
            } 
        }
 
 
        /// 
        ///     Gets or 
        ///       sets the display height (in rows) of the list box.
        /// 
        [
        WebCategory("Appearance"), 
        DefaultValue(4),
        WebSysDescription(SR.ListBox_Rows) 
        ] 
        public virtual int Rows {
            get { 
                object n = ViewState["Rows"];
                return((n == null) ? 4 : (int)n);
            }
            set { 
                if (value < 1) {
                    throw new ArgumentOutOfRangeException("value"); 
                } 
                ViewState["Rows"] = value;
            } 
        }


        ///  
        ///    Gets or sets
        ///       the selection behavior of the list box. 
        ///  
        [
        WebCategory("Behavior"), 
        DefaultValue(ListSelectionMode.Single),
        WebSysDescription(SR.ListBox_SelectionMode)
        ]
        public virtual ListSelectionMode SelectionMode { 
            get {
                object sm = ViewState["SelectionMode"]; 
                return((sm == null) ? ListSelectionMode.Single : (ListSelectionMode)sm); 
            }
            set { 
                if (value < ListSelectionMode.Single || value > ListSelectionMode.Multiple) {
                    throw new ArgumentOutOfRangeException("value");
                }
                ViewState["SelectionMode"] = value; 
            }
        } 
 

        ///  
        protected override void AddAttributesToRender(HtmlTextWriter writer) {
            writer.AddAttribute(HtmlTextWriterAttribute.Size,
                                        Rows.ToString(NumberFormatInfo.InvariantInfo));
 
            string uniqueID = UniqueID;
            if (uniqueID != null) { 
                writer.AddAttribute(HtmlTextWriterAttribute.Name, uniqueID); 
            }
 
            base.AddAttributesToRender(writer);
        }

 
        public virtual int[] GetSelectedIndices() {
            return (int[])SelectedIndicesInternal.ToArray(typeof(int)); 
        } 

 
        /// 
        /// 
        /// 
        protected internal override void OnPreRender(EventArgs e) { 
            base.OnPreRender(e);
            if (Page != null && SelectionMode == ListSelectionMode.Multiple && Enabled) { 
 
                // ensure postback when no item is selected
                Page.RegisterRequiresPostBack(this); 
            }
        }

 
        /// 
        ///  
        /// Loads the posted content of the list control if it is different from the last 
        /// posting.
        ///  
        bool IPostBackDataHandler.LoadPostData(String postDataKey, NameValueCollection postCollection) {
            return LoadPostData(postDataKey, postCollection);
        }
 

        ///  
        ///  
        /// Loads the posted content of the list control if it is different from the last
        /// posting. 
        /// 
        protected virtual bool LoadPostData(String postDataKey, NameValueCollection postCollection) {
            if (IsEnabled == false) {
                // When a ListBox is disabled, then there is no postback 
                // data for it. Any checked state information has been loaded
                // via view state. 
                return false; 
            }
 
            string[] selectedItems = postCollection.GetValues(postDataKey);
            bool selectionChanged = false;

            EnsureDataBound(); 
            if (selectedItems != null) {
                if (SelectionMode == ListSelectionMode.Single) { 
 
                    ValidateEvent(postDataKey, selectedItems[0]);
 
                    int n = Items.FindByValueInternal(selectedItems[0], false);
                    if (SelectedIndex != n) {
                        SetPostDataSelection(n);
                        selectionChanged = true; 
                    }
                } 
                else { // multiple selection 
                    int count = selectedItems.Length;
                    ArrayList oldSelectedIndices = SelectedIndicesInternal; 
                    ArrayList newSelectedIndices = new ArrayList(count);
                    for (int i=0; i < count; i++) {

                        ValidateEvent(postDataKey, selectedItems[i]); 

                        // create array of new indices from posted values 
                        newSelectedIndices.Add(Items.FindByValueInternal(selectedItems[i], false)); 
                    }
 
                    int oldcount = 0;
                    if (oldSelectedIndices != null)
                        oldcount = oldSelectedIndices.Count;
 
                    if (oldcount == count) {
                        // check new indices against old indices 
                        // assumes selected values are posted in order 
                        for (int i=0; i < count; i++) {
                            if (((int)newSelectedIndices[i]) != ((int)oldSelectedIndices[i])) { 
                                selectionChanged = true;
                                break;
                            }
                        } 
                    }
                    else { 
                        // indices must have changed if count is different 
                        selectionChanged = true;
                    } 

                    if (selectionChanged) {
                        // select new indices
                        SelectInternal(newSelectedIndices); 
                    }
                } 
            } 
            else { // no items selected
                if (SelectedIndex != -1) { 
                    SetPostDataSelection(-1);
                    selectionChanged = true;
                }
            } 

            return selectionChanged; 
        } 

 
        /// 
        /// 
        /// Invokes the OnSelectedIndexChanged method whenever posted data
        /// for the  control has changed. 
        /// 
        void IPostBackDataHandler.RaisePostDataChangedEvent() { 
            RaisePostDataChangedEvent(); 
        }
 

        /// 
        /// 
        /// Invokes the OnSelectedIndexChanged method whenever posted data 
        /// for the  control has changed.
        ///  
        protected virtual void RaisePostDataChangedEvent() { 
            if (AutoPostBack && !Page.IsPostBackEventControlRegistered) {
                // VSWhidbey 204824 
                Page.AutoPostBackControl = this;

                if (CausesValidation) {
                    Page.Validate(ValidationGroup); 
                }
            } 
            OnSelectedIndexChanged(EventArgs.Empty); 
        }
    } 
}

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

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