ITypedList 接口
定义
提供发现可绑定列表架构的功能,其中可用于绑定的属性不同于要绑定到的对象的公共属性。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 class ITypedList
public interface ITypedList
type ITypedList = interface
Public Interface ITypedList
- 派生
示例
下面的代码示例演示如何实现 ITypedList 接口。The following code example demonstrates how to implement the ITypedList interface. 名为的泛型类型 SortableBindingList 从 BindingList<T> 类派生并实现 ITypedList 接口。A generic type named SortableBindingList derives from the BindingList<T> class and implements the ITypedList interface. 有关完整的代码清单,请参阅 如何:实现 ITypedList 接口。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
}
}
Imports System.ComponentModel
Imports System.Collections.Generic
Imports System.Windows.Forms
<Serializable()> _
Public Class SortableBindingList(Of Tkey)
Inherits BindingList(Of Tkey)
Implements ITypedList
<NonSerialized()> _
Private properties As PropertyDescriptorCollection
Public Sub New()
MyBase.New()
' Get the 'shape' of the list.
' Only get the public properties marked with Browsable = true.
Dim pdc As PropertyDescriptorCollection = TypeDescriptor.GetProperties(GetType(Tkey), New Attribute() {New BrowsableAttribute(True)})
' Sort the properties.
properties = pdc.Sort()
End Sub
#Region "ITypedList Implementation"
Public Function GetItemProperties(ByVal listAccessors() As System.ComponentModel.PropertyDescriptor) As System.ComponentModel.PropertyDescriptorCollection Implements System.ComponentModel.ITypedList.GetItemProperties
Dim pdc As PropertyDescriptorCollection
If (Not (listAccessors Is Nothing)) And (listAccessors.Length > 0) Then
' Return child list shape
pdc = ListBindingHelper.GetListItemProperties(listAccessors(0).PropertyType)
Else
' Return properties in sort order
pdc = properties
End If
Return pdc
End Function
' This method is only used in the design-time framework
' and by the obsolete DataGrid control.
Public Function GetListName( _
ByVal listAccessors() As PropertyDescriptor) As String _
Implements System.ComponentModel.ITypedList.GetListName
Return GetType(Tkey).Name
End Function
#End Region
End Class
注解
例如,如果使用 DataView 表示表的对象 customer ,则需要绑定到表示的对象的属性 customer DataView ,而不是绑定的属性 DataView 。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.
对于可绑定列表的设计时支持,不需要此接口。This interface is not required for design-time support of a bindable list.
绑定到数据可在运行时或在设计器中发生,但同时存在这两种情况的规则。Binding to data can occur either at run time or in a designer, but there are rules for both. 在运行时,可以通过以下任一操作绑定到数据:At run time, you can bind to data in any of the following:
的实施者 IList ,前提是实施者有一个强类型的 Item[] 属性 (也就是说,它 Type 是但 Object) 的。Implementer of IList, provided the implementer has a strongly typed Item[] property (that is, the Type is anything but Object). 您可以通过将默认实现设为私有来实现此目的 Item[] 。You can accomplish this by making the default implementation of Item[] private. 如果要创建 IList 遵循强类型集合的规则的,则应派生自 CollectionBase 。If you want to create an IList that follows the rules of a strongly typed collection, you should derive from CollectionBase.
的实施者 ITypedList 。Implementer of ITypedList.
在设计器中,可以 Component 遵循相同的规则来初始化到对象的绑定。In a designer, you can initialize binding to Component objects by following the same rules.
有关绑定到数据源的详细信息,请参阅 System.Windows.Forms.Binding 类。For more information on binding to a data source, see the System.Windows.Forms.Binding class.
方法
| GetItemProperties(PropertyDescriptor[]) |
返回 PropertyDescriptorCollection,其表示每一项上用于绑定数据的属性。Returns the PropertyDescriptorCollection that represents the properties on each item used to bind data. |
| GetListName(PropertyDescriptor[]) |
返回列表名称。Returns the name of the list. |