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ITypedList Interface

Definition

Provides functionality to discover the schema for a bindable list, where the properties available for binding differ from the public properties of the object to bind to.

public interface ITypedList
Derived

Examples

The following code example demonstrates how to implement the ITypedList interface. A generic type named SortableBindingList derives from the BindingList<T> class and implements the ITypedList interface. For a full code listing, see How to: Implement the ITypedList Interface.

using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;
using System.Windows.Forms;
using System.Collections;
using System.Reflection;

namespace ITypedListCS
{
    [Serializable()]
    public class SortableBindingList<T> : BindingList<T>, ITypedList
    {
        [NonSerialized()]
        private PropertyDescriptorCollection properties;

        public SortableBindingList() : base()
        {
            // Get the 'shape' of the list. 
            // Only get the public properties marked with Browsable = true.
            PropertyDescriptorCollection pdc = TypeDescriptor.GetProperties(
                typeof(T), 
                new Attribute[] { new BrowsableAttribute(true) });

            // Sort the properties.
            properties = pdc.Sort();
        }

        #region ITypedList Implementation

        public PropertyDescriptorCollection GetItemProperties(PropertyDescriptor[] listAccessors)
        {
            PropertyDescriptorCollection pdc;

            if (listAccessors!=null && listAccessors.Length>0)
            {
                // Return child list shape.
                pdc = ListBindingHelper.GetListItemProperties(listAccessors[0].PropertyType);
            }
            else
            {
                // Return properties in sort order.
                pdc = properties;
            }

            return pdc;
        }

        // This method is only used in the design-time framework 
        // and by the obsolete DataGrid control.
        public string GetListName(PropertyDescriptor[] listAccessors)
        {   
            return typeof(T).Name;
        }

        #endregion
    }
}

Remarks

Use this interface if, for instance, you are using a DataView object that represents a customer table, you want to bind to the properties on the customer object that the DataView represents, not the properties of the DataView.

This interface is not required for design-time support of a bindable list.

Binding to data can occur either at run time or in a designer, but there are rules for both. At run time, you can bind to data in any of the following:

  • Array

  • Implementer of IList, provided the implementer has a strongly typed Item[] property (that is, the Type is anything but Object). You can accomplish this by making the default implementation of Item[] private. If you want to create an IList that follows the rules of a strongly typed collection, you should derive from CollectionBase.

  • Implementer of ITypedList.

In a designer, you can initialize binding to Component objects by following the same rules.

For more information on binding to a data source, see the System.Windows.Forms.Binding class.

Methods

GetItemProperties(PropertyDescriptor[])

Returns the PropertyDescriptorCollection that represents the properties on each item used to bind data.

GetListName(PropertyDescriptor[])

Returns the name of the list.

Applies to

Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0, 2.1

See also