ListDataHelper.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 / MIT / System / Web / UI / MobileControls / ListDataHelper.cs / 1305376 / ListDataHelper.cs

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

using System.Collections; 
using System.Diagnostics; 

namespace System.Web.UI.MobileControls 
{
    /*
     * List Data Helper class.
     * 
     * Copyright (c) 2000 Microsoft Corporation
     */ 
 
    [Obsolete("The System.Web.Mobile.dll assembly has been deprecated and should no longer be used. For information about how to develop ASP.NET mobile applications, see http://go.microsoft.com/fwlink/?LinkId=157231.")]
    internal sealed class ListDataHelper 
    {
        private IListControl _parent;
        private StateBag _parentViewState;
        private MobileListItemCollection _items; 
        private Object _dataSource;
        private IEnumerable _resolvedDataSource; 
        private int _dataSourceCount = -1; 
        private String _dataTextField;
        private String _dataValueField; 
        private bool _bindFromFields;

        internal /*public*/ ListDataHelper(IListControl parent, StateBag parentViewState)
        { 
            _parent = parent;
            _parentViewState = parentViewState; 
        } 

        internal /*public*/ MobileListItemCollection Items 
        {
            get
            {
                if (_items == null) 
                {
                    _items = new MobileListItemCollection(); 
                    if (_parent.TrackingViewState) 
                    {
                        ((IStateManager)_items).TrackViewState(); 
                    }
                }
                return _items;
            } 
        }
 
        internal /*public*/ bool HasItems() 
        {
            return _items != null; 
        }

        internal /*public*/ Object DataSource
        { 
            get
            { 
                return _dataSource; 
            }
 
            set
            {
                _dataSource = value;
                _resolvedDataSource = null; 
            }
        } 
 
        internal /*public*/ String DataMember
        { 
            get
            {
                String s = (String)_parentViewState["DataMember"];
                return s == null ? String.Empty : s; 
            }
 
            set 
            {
                _parentViewState["DataMember"] = value; 
            }
        }

        internal /*public*/ String DataTextField 
        {
            get 
            { 
                String s = (String)_parentViewState["DataTextField"];
                return (s != null) ? s : String.Empty; 
            }
            set
            {
                _parentViewState["DataTextField"] = value; 
            }
        } 
 
        internal /*public*/ String DataValueField
        { 
            get
            {
                String s = (String)_parentViewState["DataValueField"];
                return (s != null) ? s : String.Empty; 
            }
            set 
            { 
                _parentViewState["DataValueField"] = value;
            } 
        }

        internal /*public*/ IEnumerable ResolvedDataSource
        { 
            get
            { 
                if (_resolvedDataSource == null) 
                {
                    _resolvedDataSource = 
                        DataSourceHelper.GetResolvedDataSource(DataSource, DataMember);
                }
                return _resolvedDataSource;
            } 
        }
 
        /* 
        internal int DataSourceCount
        { 
            get
            {
                if (_dataSourceCount == -1)
                { 
                    IEnumerable dataSource = ResolvedDataSource;
                    if (dataSource != null) 
                    { 
                        ICollection collection = dataSource as ICollection;
                        if (collection != null) 
                        {
                            _dataSourceCount = collection.Count;
                        }
                        else 
                        {
                            int count = 0; 
                            IEnumerator enumerator = dataSource.GetEnumerator(); 
                            while (enumerator.MoveNext())
                            { 
                                count++;
                            }
                            _dataSourceCount = count;
                        } 
                    }
                    else 
                    { 
                        _dataSourceCount = 0;
                    } 
                }
                return _dataSourceCount;
            }
        } 
        */
 
        internal /*public*/ void CreateItems(IEnumerable dataSource) 
        {
            Debug.Assert (dataSource != null); 
            Items.Clear();
            _dataTextField = DataTextField;
            _dataValueField = DataValueField;
            _bindFromFields = (_dataTextField.Length > 0) || (_dataValueField.Length > 0); 
            foreach (Object dataItem in dataSource)
            { 
                MobileListItem listItem = CreateItem(dataItem); 

                if (listItem != null) 
                {
                    AddItem(listItem);
                }
            } 
            _dataSourceCount = Items.Count;
        } 
 
        private MobileListItem CreateItem(Object dataItem)
        { 
            MobileListItem listItem = null;
            String textField = null;
            String valueField = null;
 
            if (_bindFromFields)
            { 
                if (_dataTextField.Length > 0) 
                {
                    textField = DataBinder.GetPropertyValue(dataItem, _dataTextField, "{0}"); 
                }
                if (_dataValueField.Length > 0)
                {
                    valueField = DataBinder.GetPropertyValue(dataItem, _dataValueField, "{0}"); 
                }
            } 
            else 
            {
                textField = dataItem.ToString(); 
            }
            listItem = new MobileListItem(dataItem, textField, valueField);

            // Use delegated data binding, if specified. 
            if (dataItem != null)
            { 
                _parent.OnItemDataBind(new ListDataBindEventArgs(listItem, dataItem)); 
            }
 
            return listItem;
        }

        internal /*public*/ void AddItem(MobileListItem item) 
        {
            MobileListItemCollection items = Items; 
            items.Add(item); 
        }
    } 
}

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

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