BindingSource Class

Definition

public ref class BindingSource : System::ComponentModel::Component, System::Collections::IList, System::ComponentModel::IBindingListView, System::ComponentModel::ICancelAddNew, System::ComponentModel::ISupportInitializeNotification, System::ComponentModel::ITypedList, System::Windows::Forms::ICurrencyManagerProvider

public ref class BindingSource : System::ComponentModel::Component, System::Collections::IList, System::ComponentModel::IBindingListView, System::ComponentModel::ICancelAddNew, System::ComponentModel::ISupportInitialize, System::ComponentModel::ISupportInitializeNotification, System::ComponentModel::ITypedList, System::Windows::Forms::ICurrencyManagerProvider

[System.ComponentModel.ComplexBindingProperties("DataSource", "DataMember")]
public class BindingSource : System.ComponentModel.Component, System.Collections.IList, System.ComponentModel.IBindingListView, System.ComponentModel.ICancelAddNew, System.ComponentModel.ISupportInitializeNotification, System.ComponentModel.ITypedList, System.Windows.Forms.ICurrencyManagerProvider

[System.ComponentModel.ComplexBindingProperties("DataSource", "DataMember")]
public class BindingSource : System.ComponentModel.Component, System.Collections.IList, System.ComponentModel.IBindingListView, System.ComponentModel.ICancelAddNew, System.ComponentModel.ISupportInitialize, System.ComponentModel.ISupportInitializeNotification, System.ComponentModel.ITypedList, System.Windows.Forms.ICurrencyManagerProvider

[<System.ComponentModel.ComplexBindingProperties("DataSource", "DataMember")>]
type BindingSource = class
    inherit Component
    interface IBindingListView
    interface IBindingList
    interface IList
    interface ICollection
    interface IEnumerable
    interface ITypedList
    interface ICancelAddNew
    interface ISupportInitializeNotification
    interface ISupportInitialize
    interface ICurrencyManagerProvider

[<System.ComponentModel.ComplexBindingProperties("DataSource", "DataMember")>]
type BindingSource = class
    inherit Component
    interface IBindingListView
    interface ICollection
    interface IEnumerable
    interface IList
    interface IBindingList
    interface ITypedList
    interface ICancelAddNew
    interface ISupportInitializeNotification
    interface ISupportInitialize
    interface ICurrencyManagerProvider

Public Class BindingSource
Inherits Component
Implements IBindingListView, ICancelAddNew, ICurrencyManagerProvider, IList, ISupportInitializeNotification, ITypedList

Public Class BindingSource
Inherits Component
Implements IBindingListView, ICancelAddNew, ICurrencyManagerProvider, IList, ISupportInitialize, ISupportInitializeNotification, ITypedList

Inheritance

Object

MarshalByRefObject

Component

BindingSource

Attributes

ComplexBindingPropertiesAttribute

Implements

ICollection IEnumerable IList IBindingList IBindingListView ICancelAddNew ISupportInitialize ISupportInitializeNotification ITypedList ICurrencyManagerProvider

Examples

The following code example demonstrates a ListBox bound to a BindingSource. The BindingSource is bound to a BindingList<T> that contains a list of fonts.

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

namespace BindingSourceExamples
{
    public class Form1 : Form
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }

        public Form1()
        {
            this.Load += new EventHandler(Form1_Load);
        }

        private TextBox textBox1;
        private Button button1;
        private ListBox listBox1;
       
        private BindingSource binding1;
        void Form1_Load(object sender, EventArgs e)
        {
            listBox1 = new ListBox();
            textBox1 = new TextBox();
            binding1 = new BindingSource();
            button1 = new Button();
            listBox1.Location = new Point(140, 25);
            listBox1.Size = new Size(123, 160);
            textBox1.Location = new Point(23, 70);
            textBox1.Size = new Size(100, 20);
            textBox1.Text = "Wingdings";
            button1.Location = new Point(23, 25);
            button1.Size = new Size(75, 23);
            button1.Text = "Search";
            button1.Click += new EventHandler(this.button1_Click);
            this.ClientSize = new Size(292, 266);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.textBox1);
            this.Controls.Add(this.listBox1);

            MyFontList fonts = new MyFontList();
            for (int i = 0; i < FontFamily.Families.Length; i++)
            {
                if (FontFamily.Families[i].IsStyleAvailable(FontStyle.Regular))
                    fonts.Add(new Font(FontFamily.Families[i], 11.0F, FontStyle.Regular));
            }
            binding1.DataSource = fonts;
            listBox1.DataSource = binding1;
            listBox1.DisplayMember = "Name";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (!binding1.SupportsSearching)
            {
                MessageBox.Show("Cannot search the list.");
            }
            else
            {
                int foundIndex = binding1.Find("Name", textBox1.Text);
                if (foundIndex > -1)
                    listBox1.SelectedIndex = foundIndex;
                else
                    MessageBox.Show("Font was not found.");
            }
        }
    }
    
    public class MyFontList : BindingList<Font>
    {

        protected override bool SupportsSearchingCore
        {
            get { return true; }
        }
        protected override int FindCore(PropertyDescriptor prop, object key)
        {
            // Ignore the prop value and search by family name.
            for (int i = 0; i < Count; ++i)
            {
                if (Items[i].FontFamily.Name.ToLower() == ((string)key).ToLower())
                    return i;
            }
            return -1;
        }
    }
}

Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Public Class Form1
    Inherits Form

    <STAThread()> _
    Shared Sub Main()
        Application.EnableVisualStyles()
        Application.Run(New Form1())

    End Sub

    Public Sub New()

    End Sub

    Private textBox1 As TextBox
    Private WithEvents button1 As Button
    Private listBox1 As ListBox
    Private components As IContainer
    Private binding1 As BindingSource

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        listBox1 = New ListBox()
        textBox1 = New TextBox()
        binding1 = New BindingSource()
        button1 = New Button()
        listBox1.Location = New Point(140, 25)
        listBox1.Size = New Size(123, 160)
        textBox1.Location = New Point(23, 70)
        textBox1.Size = New Size(100, 20)
        textBox1.Text = "Wingdings"
        button1.Location = New Point(23, 25)
        button1.Size = New Size(75, 23)
        button1.Text = "Search"
        Me.ClientSize = New Size(292, 266)
        Me.Controls.Add(Me.button1)
        Me.Controls.Add(Me.textBox1)
        Me.Controls.Add(Me.listBox1)

        Dim fonts As New MyFontList()
        Dim i As Integer
        For i = 0 To FontFamily.Families.Length - 1
            If FontFamily.Families(i).IsStyleAvailable(FontStyle.Regular) Then
                fonts.Add(New Font(FontFamily.Families(i), 11.0F, FontStyle.Regular))
            End If
        Next i
        binding1.DataSource = fonts
        listBox1.DataSource = binding1
        listBox1.DisplayMember = "Name"

    End Sub
    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
        Handles button1.Click

        If binding1.SupportsSearching <> True Then
            MessageBox.Show("Cannot search the list.")
        Else
            Dim foundIndex As Integer = binding1.Find("Name", textBox1.Text)
            If foundIndex > -1 Then
                listBox1.SelectedIndex = foundIndex
            Else
                MessageBox.Show("Font was not found.")
            End If
        End If

    End Sub
End Class

Public Class MyFontList
    Inherits BindingList(Of Font)

    Protected Overrides ReadOnly Property SupportsSearchingCore() As Boolean
        Get
            Return True
        End Get
    End Property
    
    Protected Overrides Function FindCore(ByVal prop As PropertyDescriptor, _
        ByVal key As Object) As Integer
        ' Ignore the prop value and search by family name.
        Dim i As Integer
        While i < Count
            If Items(i).FontFamily.Name.ToLower() = CStr(key).ToLower() Then
                Return i
            End If
            i += 1
        End While

        Return -1
    End Function
End Class

Remarks

The BindingSource component serves many purposes. First, it simplifies binding controls on a form to data by providing currency management, change notification, and other services between Windows Forms controls and data sources. This is accomplished by attaching the BindingSource component to your data source using the DataSource property. For complex binding scenarios you can optionally set the DataMember property to a specific column or list in the data source. You then bind controls to the BindingSource. All further interaction with the data is accomplished with calls to the BindingSource component. For examples on how the BindingSource can simplify the binding process, see How to: Bind Windows Forms Controls to DBNull Database Values and How to: Handle Errors and Exceptions that Occur with Databinding. Navigation and updating of the data source is accomplished through methods such as MoveNext, MoveLast, and Remove. Operations such as sorting and filtering are handled through the Sort and Filter properties. For more information on using sorting and filtering with the BindingSource, see How to: Sort and Filter ADO.NET Data with the Windows Forms BindingSource Component.

In addition, the BindingSource component can act as a strongly typed data source. Typically the type of the underlying data source is fixed through one of the following mechanisms:

• Use the Add method to add an item to the BindingSource component.

• Set the DataSource property to a list, single object, or type.

Both of these mechanisms create a strongly-typed list. For more information on how to use the BindingSource to bind to a type, see How to: Bind a Windows Forms Control to a Type. You can also use the BindingSource to bind your controls to a factory object. For more information on how to do this, see How to: Bind a Windows Forms Control to a Factory Object.

BindingSource provides members for accessing the underlying data. The current item can be retrieved through the Current property, and the entire list can be retrieved through the List property. Editing operations are supported on the current item through Current and the RemoveCurrent, EndEdit, CancelEdit and Add and AddNew methods. Although currency management is handled automatically for all underlying data source types, this class exposes a number of events, such as CurrentItemChanged and DataSourceChanged, that allow for customization.

Data sources that are bound to a BindingSource component can also be navigated and managed with the BindingNavigator class, which provides a VCR-like user interface (UI) for navigating items within a list. Although BindingNavigator can be bound to any data source, it was designed to integrate with a BindingSource component through its BindingNavigator.BindingSource property.

The default property for the BindingSource class is DataSource. The default event is CurrentChanged.

Constructors

Properties

Methods

Events

Explicit Interface Implementations

Extension Methods

Applies to

See also

• BindingSource
• BindingNavigator
• DataGridView
• CurrencyManager
• IList
• IBindingList
• IEditableObject
• BindingSource Component