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IBindingList Interface

Provides the features required to support both complex and simple scenarios when binding to a data source.

Namespace: System.ComponentModel
Assembly: System (in system.dll)

public interface IBindingList : IList, ICollection, IEnumerable
public interface IBindingList extends IList, ICollection, 
	IEnumerable
public interface IBindingList extends IList, ICollection, 
	IEnumerable
Not applicable.

This interface is implemented by the DataView class. Implementation of a method should exhibit the same behavior as the implementation of that method in the DataView class.

When you call the ApplySort or RemoveSort methods, you should raise a ListChanged event with the Reset enumeration.

When you call the AddNew method, you should raise a ListChanged event with the ItemAdded enumeration carrying the appropriate index. The added row is in a state where pressing the ESC on a DataGridView control can remove the new row. Raising the ListChanged event with the ItemAdded enumeration a second time on this row indicates that the item is now a row not in the "new" state.

When you remove an item or call the CancelEdit method on a new row (if that row implements IEditableObject), you should raise a ListChanged event with the ItemDeleted enumeration carrying the appropriate index.

The following example provides a simple implementation of the IBindingList interface. The CustomerList class stores customer information in a list. This example assumes that you have used the Customer class that can be found in the example in the IEditableObject class.

public class CustomersList :  CollectionBase, IBindingList
{

    private ListChangedEventArgs resetEvent = new ListChangedEventArgs(ListChangedType.Reset, -1);
    private ListChangedEventHandler onListChanged;

    public void LoadCustomers() 
    {
        IList l = (IList)this;
        l.Add(ReadCustomer1());
        l.Add(ReadCustomer2());
        OnListChanged(resetEvent);
    }

    public Customer this[int index] 
    {
        get 
        {
            return (Customer)(List[index]);
        }
        set 
        {
            List[index] = value;
        }
    }

    public int Add (Customer value) 
    {
        return List.Add(value);
    }

    public Customer AddNew() 
    {
        return (Customer)((IBindingList)this).AddNew();
    }

    public void Remove (Customer value) 
    {
        List.Remove(value);
    }

    
    protected virtual void OnListChanged(ListChangedEventArgs ev) 
    {
        if (onListChanged != null) 
        {
            onListChanged(this, ev);
        }
    }
    

    protected override void OnClear() 
    {
        foreach (Customer c in List) 
        {
            c.Parent = null;
        }
    }

    protected override void OnClearComplete() 
    {
        OnListChanged(resetEvent);
    }

    protected override void OnInsertComplete(int index, object value) 
    {
        Customer c = (Customer)value;
        c.Parent = this;
        OnListChanged(new ListChangedEventArgs(ListChangedType.ItemAdded, index));
    }

    protected override void OnRemoveComplete(int index, object value) 
    {
        Customer c = (Customer)value;
        c.Parent = this;
        OnListChanged(new ListChangedEventArgs(ListChangedType.ItemDeleted, index));
    }

    protected override void OnSetComplete(int index, object oldValue, object newValue) 
    {
        if (oldValue != newValue) 
        {

            Customer oldcust = (Customer)oldValue;
            Customer newcust = (Customer)newValue;
            
            oldcust.Parent = null;
            newcust.Parent = this;
            
            
            OnListChanged(new ListChangedEventArgs(ListChangedType.ItemAdded, index));
        }
    }
    
    // Called by Customer when it changes.
    internal void CustomerChanged(Customer cust) 
    {
        
        int index = List.IndexOf(cust);
        
        OnListChanged(new ListChangedEventArgs(ListChangedType.ItemChanged, index));
    }
    

    // Implements IBindingList.
    bool IBindingList.AllowEdit 
    { 
        get { return true ; }
    }

    bool IBindingList.AllowNew 
    { 
        get { return true ; }
    }

    bool IBindingList.AllowRemove 
    { 
        get { return true ; }
    }

    bool IBindingList.SupportsChangeNotification 
    { 
        get { return true ; }
    }
    
    bool IBindingList.SupportsSearching 
    { 
        get { return false ; }
    }

    bool IBindingList.SupportsSorting 
    { 
        get { return false ; }
    }


    // Events.
    public event ListChangedEventHandler ListChanged 
    {
        add 
        {
            onListChanged += value;
        }
        remove 
        {
            onListChanged -= value;
        }
    }

    // Methods.
    object IBindingList.AddNew() 
    {
        Customer c = new Customer(this.Count.ToString());
        List.Add(c);
        return c;
    }


    // Unsupported properties.
    bool IBindingList.IsSorted 
    { 
        get { throw new NotSupportedException(); }
    }

    ListSortDirection IBindingList.SortDirection 
    { 
        get { throw new NotSupportedException(); }
    }


    PropertyDescriptor IBindingList.SortProperty 
    { 
        get { throw new NotSupportedException(); }
    }


    // Unsupported Methods.
    void IBindingList.AddIndex(PropertyDescriptor property) 
    {
        throw new NotSupportedException(); 
    }

    void IBindingList.ApplySort(PropertyDescriptor property, ListSortDirection direction) 
    {
        throw new NotSupportedException(); 
    }

    int IBindingList.Find(PropertyDescriptor property, object key) 
    {
        throw new NotSupportedException(); 
    }

    void IBindingList.RemoveIndex(PropertyDescriptor property) 
    {
        throw new NotSupportedException(); 
    }

    void IBindingList.RemoveSort() 
    {
        throw new NotSupportedException(); 
    }

    // Worker functions to populate the list with data.
    private static Customer ReadCustomer1() 
    {
        Customer cust = new Customer("536-45-1245");
        cust.FirstName = "Jo";
        cust.LastName = "Brown";
        return cust;
    }
    
    private static Customer ReadCustomer2() 
    {
        Customer cust = new Customer("246-12-5645");
        cust.FirstName = "Robert";
        cust.LastName = "Brown";
        return cust;
    }
}


Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0
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