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BindingList<T> Class

Provides a generic collection that supports data binding.

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

[SerializableAttribute]
[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)]
public class BindingList<T> : Collection<T>, 
	IBindingList, IList, ICollection, IEnumerable, ICancelAddNew, 
	IRaiseItemChangedEvents

Type Parameters

T

The type of elements in the list.

NoteNote:

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: SharedState. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The BindingList<T> class can be used as a base class to create a two-way data-binding mechanism. BindingList<T> provides a concrete, generic implementation of the IBindingList interface. This is an alternative to implementing the complete IBindingList interface, which can be difficult because of the subtle interaction between IBindingList, IEditableObject, and the associated CurrencyManager. However, the typical solutions programmer will use a class that provides data binding functionality, such as BindingSource, instead of directly using BindingList<T>.

BindingList<T> supports factory-created instances through the extensible AddNew method. (This same type of extensibility is also found in other classes, such as BindingSource) In addition, since this class implements the ICancelAddNew interface, it enables transactional commits or rollbacks of the new item through the EndNew and CancelNew methods.

The following code example demonstrates binding to a BindingList<T> component containing a business object. This is a complete example that contains a Main method.

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; }
        }
    }
}

System.Object
  System.Collections.ObjectModel.Collection<T>
    System.ComponentModel.BindingList<T>

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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