Товарищи девелоперы ! Кто нибудь когда-то стыкался с проблемой реализации кастом дата биндинга ? | Код |
#region file using directives
using System;
using System.ComponentModel;
using System.Collections;
using System.Reflection;
#endregion
namespace KTP.Business.Primitivies.Collections
{
/// <summary>
///
/// </summary>
public abstract class BindingCollectionBase
: IBindingList
{
#region Class members
/// <summary>
/// hash: Primary Key - to - Item
/// </summary>
private Hashtable m_items;
/// <summary>
/// Stored order of items adding/inserting into collection.
/// </summary>
private ArrayList m_itemsKey;
/// <summary>
///
/// </summary>
private bool m_bQuiet;
/// <summary>
///
/// </summary>
private ListSortDirection m_direction;
/// <summary>
///
/// </summary>
private PropertyDescriptor m_sortProperty;
/// <summary>
///
/// </summary>
private bool m_bSort;
/// <summary>
///
/// </summary>
private int m_version;
#endregion
#region Class properties
/// <summary>
/// Gets or sets item from collection by it order index.
/// </summary>
/// <param name="id">Order Index of item in collection</param>
object IList.this[ int id ]
{
get
{
return m_items[ m_itemsKey[ id ] ];
}
set
{
object obj = (( IList )this)[ id ];
if( obj != value )
{
obj = value;
RaiseListChanged( ListChangedType.ItemChanged );
}
}
}
/// <summary>
///
/// </summary>
public bool IsSynchronized
{
get
{
return m_items.IsSynchronized;
}
}
/// <summary>
///
/// </summary>
public PropertyDescriptor SortProperty
{
get
{
return m_sortProperty;
}
}
/// <summary>
/// Gets or Sets version of collection. This property used for controlling
/// live cycle of enumerators.
/// </summary>
protected internal int Version
{
get
{
return m_version;
}
set
{
m_version = value;
}
}
/// <summary>
/// Get hash table that contains pair primary_key-to-item.
/// </summary>
protected Hashtable InnerHash
{
get
{
return m_items;
}
}
/// <summary>
///
/// </summary>
protected abstract string PrimaryIndexPropertyName{ get; }
#endregion
#region Class events
/// <summary>
///
/// </summary>
public event ListChangedEventHandler ListChanged;
#endregion
#region Class Initialize/Finalize methods
/// <summary>
///
/// </summary>
protected BindingCollectionBase()
{
m_items = new Hashtable();
m_itemsKey = new ArrayList();
m_direction = ListSortDirection.Ascending;
}
#endregion
/// <summary>
///
/// </summary>
/// <returns></returns>
IEnumerator IEnumerable.GetEnumerator()
{
return m_items.GetEnumerator();
}
#endregion
/// <summary>
/// IComparer hierarchy class for Descending type sorting
/// </summary>
internal class ComparerDescending : IComparer
{
#region Class members
/// <summary>
///
/// </summary>
private static readonly ComparerDescending _default = new ComparerDescending();
#endregion
#region Class static properties
/// <summary>
///
/// </summary>
public static IComparer Default
{
get
{
return _default;
}
}
#endregion
#region Class Initialize/Finalize methods
/// <summary>
///
/// </summary>
private ComparerDescending()
{
}
#endregion
#region IComparer Members
/// <summary>
///
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public int Compare( object x, object y )
{
return -CaseInsensitiveComparer.DefaultInvariant.Compare( x, y );
}
#endregion
}
/// <summary>
///
/// </summary>
public class CollectionPropertyDescriptor
: PropertyDescriptor
{
#region Class members
/// <summary>
///
/// </summary>
private PropertyInfo m_info;
/// <summary>
///
/// </summary>
private Type m_collectionType;
#endregion
#region Class properties
/// <summary>
///
/// </summary>
public override Type ComponentType
{
get
{
return m_collectionType;
}
}
/// <summary>
///
/// </summary>
public override Type PropertyType
{
get
{
return m_info.PropertyType;
}
}
/// <summary>
///
/// </summary>
public override bool IsReadOnly
{
get
{
return true;
}
}
#endregion
#region Class Initialize/Finalize methods
/// <summary>
/// Create property description for BindingCollection classes
/// </summary>
/// <param name="memberName"> Name of member </param>
/// <param name="type"> type of collection items </param>
public CollectionPropertyDescriptor( string memberName, Type type )
: base( memberName, null )
{
if( null == memberName )
throw new ArgumentNullException( "memberName" );
if( 0 == memberName.Length )
throw new ArgumentException( "memberName - string can not be empty" );
m_collectionType = type;
m_info = type.GetProperty( this.Name );
if( m_info == null )
throw new ArgumentNullException( "Vacation type doesn't have '" + memberName + "' property." );
}
#endregion
#region Class overrides
/// <summary>
///
/// </summary>
/// <param name="component"></param>
/// <returns></returns>
public override bool ShouldSerializeValue( object component )
{
return false;
}
/// <summary>
///
/// </summary>
/// <param name="component"></param>
public override void ResetValue( object component )
{
// do nothing
}
/// <summary>
///
/// </summary>
/// <param name="component"></param>
/// <returns></returns>
public override bool CanResetValue( object component )
{
return false;
}
/// <summary>
/// Get value of property by component Vacation object
/// </summary>
/// <param name="component"></param>
/// <returns> value of </returns>
public override object GetValue( object component )
{
object result = null;
//if( component is ComponentType )
{
result = m_collectionType.GetProperty( this.Name ).GetValue( component, null );
}
return result;
}
/// <summary>
///
/// </summary>
/// <param name="component"></param>
/// <param name="value"></param>
public override void SetValue( object component, object value )
{
// do nothing
}
#endregion
}
}
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код я немного сократил, а то он немножко большой. Как видете класик имплементит интерфейс IBindingList. Коллекция была переработана так, чтобы по индексатору был доступ к елементам по их ID ( данные берутся с БД ). Соответсвенно чтобы получить елемент с 0 индексом ( не ID ) нужно приводить переменную к IList. Проблема такова. Когда я соединяю колекцию с ComboBox через DataSource, контрол не правильно выгребает данные. Вместо конкретного типа елемента, ему выкидывается DictionaryEntry с хеш таблицы. При попытке такой же завязки на мой собственный комбобокс, была такая же проблема. Но она решилась путём замены в коде разборки данных foreach на for. Но здесь проблема не решается. Я пока так и не понял как же подсунуть вместо DictionaryEntry, свой тип. Кстати интересно что при ручном дебаге, через foreach всё ок. А вот ComboBox..... |
Custom DataBinding, проблема при завязке на контрол 
Дата 12.6.2006, 23:47 (
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