BindingList<T> 类
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
提供支持数据绑定的泛型集合。
generic <typename T>
public ref class BindingList : System::Collections::ObjectModel::Collection<T>, System::ComponentModel::IBindingList, System::ComponentModel::ICancelAddNew, System::ComponentModel::IRaiseItemChangedEvents
public class BindingList<T> : System.Collections.ObjectModel.Collection<T>, System.ComponentModel.IBindingList, System.ComponentModel.ICancelAddNew, System.ComponentModel.IRaiseItemChangedEvents
[System.Serializable]
public class BindingList<T> : System.Collections.ObjectModel.Collection<T>, System.ComponentModel.IBindingList, System.ComponentModel.ICancelAddNew, System.ComponentModel.IRaiseItemChangedEvents
type BindingList<'T> = class
inherit Collection<'T>
interface ICollection
interface IEnumerable
interface IList
interface IBindingList
interface ICancelAddNew
interface IRaiseItemChangedEvents
[<System.Serializable>]
type BindingList<'T> = class
inherit Collection<'T>
interface IBindingList
interface IList
interface ICollection
interface IEnumerable
interface ICancelAddNew
interface IRaiseItemChangedEvents
Public Class BindingList(Of T)
Inherits Collection(Of T)
Implements IBindingList, ICancelAddNew, IRaiseItemChangedEvents
类型参数
- T
列表中元素的类型。
- 继承
- 属性
- 实现
示例
下面的代码示例演示如何绑定到 BindingList<T> 包含业务对象的组件。 这是一个包含 Main
方法的完整示例。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace BindingListOfTExamples
{
public partial class Form1 : Form
{
private TextBox textBox2;
private ListBox listBox1;
private Button button1;
private TextBox textBox1;
Random randomNumber = new Random();
public Form1()
{
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.textBox1 = new System.Windows.Forms.TextBox();
this.textBox2 = new System.Windows.Forms.TextBox();
this.listBox1 = new System.Windows.Forms.ListBox();
this.button1 = new System.Windows.Forms.Button();
this.textBox1.Location = new System.Drawing.Point(169, 26);
this.textBox1.Size = new System.Drawing.Size(100, 20);
this.textBox1.Text = "Bracket";
this.textBox2.Location = new System.Drawing.Point(169, 57);
this.textBox2.ReadOnly = true;
this.textBox2.Size = new System.Drawing.Size(100, 20);
this.textBox2.Text = "4343";
this.listBox1.FormattingEnabled = true;
this.listBox1.Location = new System.Drawing.Point(12, 12);
this.listBox1.Size = new System.Drawing.Size(120, 95);
this.button1.Location = new System.Drawing.Point(180, 83);
this.button1.Size = new System.Drawing.Size(75, 23);
this.button1.Text = "Add New Item";
this.button1.Click += new System.EventHandler(this.button1_Click);
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.button1);
this.Controls.Add(this.listBox1);
this.Controls.Add(this.textBox2);
this.Controls.Add(this.textBox1);
this.Text = "Parts Form";
this.Load += new EventHandler(Form1_Load);
}
void Form1_Load(object sender, EventArgs e)
{
InitializeListOfParts();
listBox1.DataSource = listOfParts;
listBox1.DisplayMember = "PartName";
listOfParts.AddingNew += new AddingNewEventHandler(listOfParts_AddingNew);
listOfParts.ListChanged += new ListChangedEventHandler(listOfParts_ListChanged);
}
// Declare a new BindingListOfT with the Part business object.
BindingList<Part> listOfParts;
private void InitializeListOfParts()
{
// Create the new BindingList of Part type.
listOfParts = new BindingList<Part>();
// Allow new parts to be added, but not removed once committed.
listOfParts.AllowNew = true;
listOfParts.AllowRemove = false;
// Raise ListChanged events when new parts are added.
listOfParts.RaiseListChangedEvents = true;
// Do not allow parts to be edited.
listOfParts.AllowEdit = false;
// Add a couple of parts to the list.
listOfParts.Add(new Part("Widget", 1234));
listOfParts.Add(new Part("Gadget", 5647));
}
// Create a new part from the text in the two text boxes.
void listOfParts_AddingNew(object sender, AddingNewEventArgs e)
{
e.NewObject = new Part(textBox1.Text, int.Parse(textBox2.Text));
}
// Add the new part unless the part number contains
// spaces. In that case cancel the add.
private void button1_Click(object sender, EventArgs e)
{
Part newPart = listOfParts.AddNew();
if (newPart.PartName.Contains(" "))
{
MessageBox.Show("Part names cannot contain spaces.");
listOfParts.CancelNew(listOfParts.IndexOf(newPart));
}
else
{
textBox2.Text = randomNumber.Next(9999).ToString();
textBox1.Text = "Enter part name";
}
}
void listOfParts_ListChanged(object sender, ListChangedEventArgs e)
{
MessageBox.Show(e.ListChangedType.ToString());
}
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.Run(new Form1());
}
}
// A simple business object for example purposes.
public class Part
{
private string name;
private int number;
public Part() { }
public Part(string nameForPart, int numberForPart)
{
PartName = nameForPart;
PartNumber = numberForPart;
}
public string PartName
{
get { return name; }
set { name = value; }
}
public int PartNumber
{
get { return number; }
set { number = value; }
}
}
}
Option Explicit On
Option Strict On
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Class Form1
Inherits Form
Private textBox2 As TextBox
Private listBox1 As ListBox
Private WithEvents button1 As Button
Private textBox1 As TextBox
Private randomNumber As New Random()
Public Sub New()
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
Me.textBox1 = New System.Windows.Forms.TextBox()
Me.textBox2 = New System.Windows.Forms.TextBox()
Me.listBox1 = New System.Windows.Forms.ListBox()
Me.button1 = New System.Windows.Forms.Button()
Me.textBox1.Location = New System.Drawing.Point(169, 26)
Me.textBox1.Size = New System.Drawing.Size(100, 20)
Me.textBox1.Text = "Bracket"
Me.textBox2.Location = New System.Drawing.Point(169, 57)
Me.textBox2.ReadOnly = True
Me.textBox2.Size = New System.Drawing.Size(100, 20)
Me.textBox2.Text = "4343"
Me.listBox1.FormattingEnabled = True
Me.listBox1.Location = New System.Drawing.Point(12, 12)
Me.listBox1.Size = New System.Drawing.Size(120, 95)
Me.button1.Location = New System.Drawing.Point(180, 83)
Me.button1.Size = New System.Drawing.Size(75, 23)
Me.button1.Text = "Add New Item"
Me.ClientSize = New System.Drawing.Size(292, 266)
Me.Controls.Add(Me.button1)
Me.Controls.Add(Me.listBox1)
Me.Controls.Add(Me.textBox2)
Me.Controls.Add(Me.textBox1)
Me.Text = "Parts Form"
AddHandler Me.Load, AddressOf Form1_Load
End Sub
Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
InitializeListOfParts()
listBox1.DataSource = listOfParts
listBox1.DisplayMember = "PartName"
End Sub
' Declare a new BindingListOfT with the Part business object.
Private WithEvents listOfParts As BindingList(Of Part)
Private Sub InitializeListOfParts()
' Create the new BindingList of Part type.
listOfParts = New BindingList(Of Part)
' Allow new parts to be added, but not removed once committed.
listOfParts.AllowNew = True
listOfParts.AllowRemove = False
' Raise ListChanged events when new parts are added.
listOfParts.RaiseListChangedEvents = True
' Do not allow parts to be edited.
listOfParts.AllowEdit = False
' Add a couple of parts to the list.
listOfParts.Add(New Part("Widget", 1234))
listOfParts.Add(New Part("Gadget", 5647))
End Sub
' Create a new part from the text in the two text boxes.
Private Sub listOfParts_AddingNew(ByVal sender As Object, _
ByVal e As AddingNewEventArgs) Handles listOfParts.AddingNew
e.NewObject = New Part(textBox1.Text, Integer.Parse(textBox2.Text))
End Sub
' Add the new part unless the part number contains
' spaces. In that case cancel the add.
Private Sub button1_Click(ByVal sender As Object, _
ByVal e As EventArgs) Handles button1.Click
Dim newPart As Part = listOfParts.AddNew()
If newPart.PartName.Contains(" ") Then
MessageBox.Show("Part names cannot contain spaces.")
listOfParts.CancelNew(listOfParts.IndexOf(newPart))
Else
textBox2.Text = randomNumber.Next(9999).ToString()
textBox1.Text = "Enter part name"
End If
End Sub
<STAThread()> _
Shared Sub Main()
Application.EnableVisualStyles()
Application.Run(New Form1())
End Sub
End Class
' A simple business object for example purposes.
Public Class Part
Private name As String
Private number As Integer
Public Sub New()
End Sub
Public Sub New(ByVal nameForPart As String, _
ByVal numberForPart As Integer)
PartName = nameForPart
PartNumber = numberForPart
End Sub
Public Property PartName() As String
Get
Return name
End Get
Set(ByVal value As String)
name = Value
End Set
End Property
Public Property PartNumber() As Integer
Get
Return number
End Get
Set(ByVal value As Integer)
number = Value
End Set
End Property
End Class
注解
类 BindingList<T> 可用作基类,以创建双向数据绑定机制。 BindingList<T> 提供 接口的具体泛型实现 IBindingList 。 这是实现完整IBindingList接口的替代方法,由于 、 IEditableObject和关联的 CurrencyManager之间的IBindingList细微交互,这可能很困难。 但是,典型的解决方案程序员将使用提供数据绑定功能的类,例如 BindingSource,而不是直接使用 BindingList<T>。
BindingList<T> 通过可扩展 AddNew 方法支持工厂创建的实例。 (这种相同类型的扩展性也存在于其他类中,例如 BindingSource) 此外,由于此类实现 ICancelAddNew 接口,因此它通过 EndNew 和 CancelNew 方法启用新项的事务提交或回滚。
构造函数
BindingList<T>() |
使用默认值初始化 BindingList<T> 类的新实例。 |
BindingList<T>(IList<T>) |
使用指定列表初始化 BindingList<T> 类的新实例。 |
属性
AllowEdit |
获取或设置一个值,该值指示该列表中的项是否可以编辑。 |
AllowNew |
获取或设置一个值,该值指示是否可以使用 AddNew() 方法向列表中添加项。 |
AllowRemove |
获取或设置一个值,该值指示是否可以从集合中移除项。 |
Count |
获取 Collection<T> 中实际包含的元素数。 (继承自 Collection<T>) |
IsSortedCore |
获取一个值,指示列表是否已排序。 |
Item[Int32] |
获取或设置指定索引处的元素。 (继承自 Collection<T>) |
Items |
获取 IList<T> 周围的 Collection<T> 包装。 (继承自 Collection<T>) |
RaiseListChangedEvents |
获取或设置一个值,该值指示在列表中添加或移除项时是否会引发 ListChanged 事件。 |
SortDirectionCore |
获取列表的排序方向。 |
SortPropertyCore |
如果在派生类中实现了排序,则获取用于对列表排序的属性说明符;否则返回 |
SupportsChangeNotificationCore |
获取一个值,该值指示是否启用 ListChanged 事件。 |
SupportsSearchingCore |
获取一个值,该值指示列表是否支持搜索。 |
SupportsSortingCore |
获取一个值,该值指示列表是否支持排序。 |
方法
事件
AddingNew |
在将项添加到该列表之前发生。 |
ListChanged |
当列表或列表中的项更改时发生。 |
显式接口实现
扩展方法
适用于
另请参阅
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