IListSource Interface

Definição

Fornece funcionalidade para um objeto retornar uma lista que pode ser associada a uma fonte de dados.Provides functionality to an object to return a list that can be bound to a data source.

public interface class IListSource
public interface IListSource
[System.ComponentModel.TypeConverter("System.Windows.Forms.Design.DataSourceConverter, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public interface IListSource
[System.ComponentModel.TypeConverter("System.Windows.Forms.Design.DataSourceConverter, System.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public interface IListSource
[System.ComponentModel.TypeConverter("System.Windows.Forms.Design.DataSourceConverter, System.Design, Version=2.0.5.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public interface IListSource
type IListSource = interface
Public Interface IListSource
Derivado
Atributos

Exemplos

O exemplo de código a seguir demonstra como implementar a interface IListSource.The following code example demonstrates how to implement the IListSource interface. Um componente chamado EmployeeListSource expõe um IList para a vinculação de dados implementando o método GetList.A component named EmployeeListSource exposes an IList for data binding by implementing the GetList method. Para obter uma listagem de código completa, consulte como implementar a interface IListSource.For a full code listing, see How to: Implement the IListSource Interface.

using System;
using System.Collections.Generic;
using System.Text;
using System.ComponentModel;

namespace IListSourceCS
{
    public class EmployeeListSource : Component, IListSource
    {
        public EmployeeListSource() {}

        public EmployeeListSource(IContainer container)
        {
            container.Add(this);
        }

        #region IListSource Members

        bool IListSource.ContainsListCollection
        {
            get { return false; }
        }

        System.Collections.IList IListSource.GetList()
        {
            BindingList<Employee>   ble = new BindingList<Employee>();

            if (!this.DesignMode)
            {
                ble.Add(new Employee("Aaberg, Jesper", 26000000));
                ble.Add(new Employee("Cajhen, Janko", 19600000));
                ble.Add(new Employee("Furse, Kari", 19000000));
                ble.Add(new Employee("Langhorn, Carl", 16000000));
                ble.Add(new Employee("Todorov, Teodor", 15700000));
                ble.Add(new Employee("Verebélyi, Ágnes", 15700000));
            }

            return ble;
        }

        #endregion
    }
}
Imports System.ComponentModel

Public Class EmployeeListSource
    Inherits Component
    Implements IListSource

    <System.Diagnostics.DebuggerNonUserCode()> _
Public Sub New(ByVal Container As System.ComponentModel.IContainer)
        MyClass.New()

        'Required for Windows.Forms Class Composition Designer support
        Container.Add(Me)

    End Sub

    <System.Diagnostics.DebuggerNonUserCode()> _
    Public Sub New()
        MyBase.New()

        'This call is required by the Component Designer.
        InitializeComponent()

    End Sub

    'Component overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()> _
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing AndAlso components IsNot Nothing Then
            components.Dispose()
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Component Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Component Designer
    'It can be modified using the Component Designer.
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> _
    Private Sub InitializeComponent()
        components = New System.ComponentModel.Container()
    End Sub

#Region "IListSource Members"

    Public ReadOnly Property ContainsListCollection() As Boolean Implements System.ComponentModel.IListSource.ContainsListCollection
        Get
            Return False
        End Get
    End Property

    Public Function GetList() As System.Collections.IList Implements System.ComponentModel.IListSource.GetList

        Dim ble As New BindingList(Of Employee)

        If Not Me.DesignMode Then
            ble.Add(New Employee("Aaberg, Jesper", 26000000))
            ble.Add(New Employee("Cajhen, Janko", 19600000))
            ble.Add(New Employee("Furse, Kari", 19000000))
            ble.Add(New Employee("Langhorn, Carl", 16000000))
            ble.Add(New Employee("Todorov, Teodor", 15700000))
            ble.Add(New Employee("Verebélyi, Ágnes", 15700000))
        End If

        Return ble

    End Function

#End Region

End Class

Comentários

Normalmente, você usa essa interface para retornar uma lista que pode ser associada a uma fonte de dados, de um objeto que não implementa IList ela mesma.You typically use this interface to return a list that can be bound to a data source, from an object that does not implement IList itself.

A associação a dados pode ocorrer em tempo de execução ou em um designer, mas há regras para cada um.Binding to data can occur at either run time or in a designer, but there are rules for each. Em tempo de execução, você pode associar a dados em qualquer um dos seguintes:At run time, you can bind to data in any of the following:

  • Array

  • Implementador de IList, desde que o implementador tenha uma propriedade de Item[Int32] fortemente tipada (ou seja, o Type é algo, menos Object).Implementer of IList, provided the implementer has a strongly typed Item[Int32] property (that is, the Type is anything but Object). Você pode fazer isso tornando a implementação padrão de Item[Int32] privada.You can accomplish this by making the default implementation of Item[Int32] private. Se você quiser criar um IList que siga as regras de uma coleção com rigidez de tipos, deverá derivar de CollectionBase.If you want to create an IList that follows the rules of a strongly typed collection, you should derive from CollectionBase.

  • Implementador de ITypedList.Implementer of ITypedList.

Em um designer, você pode inicializar a associação a objetos Component seguindo as mesmas regras.In a designer, you can initialize binding to Component objects by following the same rules.

Observação

Implementadores de IListSource podem retornar um IList que contém uma coleção de objetos IList.Implementers of IListSource can return an IList that contains a collection of IList objects.

Propriedades

ContainsListCollection

Obtém um valor que indica se a coleção é uma coleção de objetos IList.Gets a value indicating whether the collection is a collection of IList objects.

Métodos

GetList()

Retorna um IList que pode ser associado a uma fonte de dados de um objeto que não implementa um IList.Returns an IList that can be bound to a data source from an object that does not implement an IList itself.

Aplica-se a

Veja também