How to: Implement the IListSource Interface

Implement the IListSource interface to create a bindable class that does not implement IList but instead provides a list from another location.

Example

The following code example demonstrates how to implement the IListSource interface. A component named EmployeeListSource exposes an IList for data binding by implementing the GetList method.

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

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

namespace IListSourceCS
{
 public class Employee : BusinessObjectBase
 {
 private string _id;
 private string _name;
 private Decimal parkingId;

 public Employee() : this(string.Empty, 0) {}
 public Employee(string name) : this(name, 0) {}

 public Employee(string name, Decimal parkingId) : base()
 {
 this._id = System.Guid.NewGuid().ToString();

 // Set values
 this.Name = name;
 this.ParkingID = parkingId;
 }

 public string ID
 {
 get { return _id; }
 }

 const string NAME = "Name";
 public string Name
 {
 get { return _name; }
 set
 {
 if (_name != value)
 {
 _name = value;

 // Raise the PropertyChanged event.
 OnPropertyChanged(NAME);
 }
 }
 }

 const string PARKING_ID = "Salary";
 public Decimal ParkingID
 {
 get { return parkingId; }
 set
 {
 if (parkingId != value)
 {
 parkingId = value;

 // Raise the PropertyChanged event.
 OnPropertyChanged(PARKING_ID);
 }
 }
 }
 }
}

Imports System.ComponentModel

Public Class Employee
 Inherits BusinessObjectBase

 Private _id As String
 Private _name As String
 Private _parkingId As Decimal

 Public Sub New(ByVal name As String, ByVal parkId As Decimal)
 MyBase.New()
 Me._id = System.Guid.NewGuid().ToString()
 ' Set values
 Me.Name = name
 Me.ParkingID = parkId
 End Sub

 Public ReadOnly Property ID() As String
 Get
 Return _id
 End Get
 End Property

 Const NAME_Const As String = "Name"

 Public Property Name() As String
 Get
 Return _name
 End Get
 Set(ByVal value As String)
 If _name <> value Then
 _name = value
 OnPropertyChanged(NAME_Const)
 End If
 End Set
 End Property

 Const PARKINGID_Const As String = "ParkingID"

 Public Property ParkingID() As Decimal
 Get
 Return _parkingId
 End Get
 Set(ByVal value As Decimal)
 If _parkingId <> value Then
 _parkingId = value
 OnPropertyChanged(PARKINGID_Const)
 End If
 End Set
 End Property

End Class

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

namespace IListSourceCS
{
 public class BusinessObjectBase : INotifyPropertyChanged
 {
 #region INotifyPropertyChanged Members

 public event PropertyChangedEventHandler PropertyChanged;

 protected virtual void OnPropertyChanged(string propertyName)
 {
 OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
 }

 private void OnPropertyChanged(PropertyChangedEventArgs e)
 {
 if (null != PropertyChanged)
 {
 PropertyChanged(this, e);
 }
 }

 #endregion
 }
}

Imports System.ComponentModel

Public Class BusinessObjectBase
 Implements INotifyPropertyChanged

#Region "INotifyPropertyChanged Members"

 Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged

 Protected Overridable Sub OnPropertyChanged(ByVal propertyName As String)
 OnPropertyChanged(New PropertyChangedEventArgs(propertyName))
 End Sub

 Private Sub OnPropertyChanged(ByVal e As PropertyChangedEventArgs)
 RaiseEvent PropertyChanged(Me, e)
 End Sub

#End Region

End Class

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

namespace IListSourceCS
{
 public class Form1 : Form
 {
 private System.ComponentModel.IContainer components = null;
 private FlowLayoutPanel flowLayoutPanel1;
 private Label label2;
 private DataGridView dataGridView1;
 private DataGridViewTextBoxColumn nameDataGridViewTextBoxColumn;
 private DataGridViewTextBoxColumn salaryDataGridViewTextBoxColumn;
 private DataGridViewTextBoxColumn iDDataGridViewTextBoxColumn;
 private EmployeeListSource employeeListSource1;

 public Form1()
 {
 InitializeComponent();
 }

 protected override void Dispose(bool disposing)
 {
 if (disposing && (components != null))
 {
 components.Dispose();
 }
 base.Dispose(disposing);
 }

 #region Windows Form Designer generated code

 private void InitializeComponent()
 {
 this.components = new System.ComponentModel.Container();
 System.Windows.Forms.DataGridViewCellStyle dataGridViewCellStyle1 = new System.Windows.Forms.DataGridViewCellStyle();
 System.Windows.Forms.DataGridViewCellStyle dataGridViewCellStyle2 = new System.Windows.Forms.DataGridViewCellStyle();
 this.flowLayoutPanel1 = new System.Windows.Forms.FlowLayoutPanel();
 this.label2 = new System.Windows.Forms.Label();
 this.dataGridView1 = new System.Windows.Forms.DataGridView();
 this.nameDataGridViewTextBoxColumn = new System.Windows.Forms.DataGridViewTextBoxColumn();
 this.salaryDataGridViewTextBoxColumn = new System.Windows.Forms.DataGridViewTextBoxColumn();
 this.iDDataGridViewTextBoxColumn = new System.Windows.Forms.DataGridViewTextBoxColumn();
 this.employeeListSource1 = new EmployeeListSource(this.components);
 this.flowLayoutPanel1.SuspendLayout();
 ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).BeginInit();
 this.SuspendLayout();
 //
 // flowLayoutPanel1
 //
 this.flowLayoutPanel1.AutoSize = true;
 this.flowLayoutPanel1.Controls.Add(this.label2);
 this.flowLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Top;
 this.flowLayoutPanel1.Location = new System.Drawing.Point(0, 0);
 this.flowLayoutPanel1.Name = "flowLayoutPanel1";
 this.flowLayoutPanel1.Size = new System.Drawing.Size(416, 51);
 this.flowLayoutPanel1.TabIndex = 11;
 //
 // label2
 //
 this.label2.AutoSize = true;
 this.label2.Location = new System.Drawing.Point(3, 6);
 this.label2.Margin = new System.Windows.Forms.Padding(3, 6, 3, 6);
 this.label2.Name = "label2";
 this.label2.Size = new System.Drawing.Size(408, 39);
 this.label2.TabIndex = 0;
 this.label2.Text = "This sample demonstrates how to implement the IListSource interface. In this sam" +
 "ple, a DataGridView is bound at design time to a Component (employeeListSource1)" +
 " that implements IListSource.";
 //
 // dataGridView1
 //
 this.dataGridView1.AllowUserToAddRows = false;
 this.dataGridView1.AllowUserToDeleteRows = false;
 dataGridViewCellStyle1.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(255)))), ((int)(((byte)(255)))), ((int)(((byte)(192)))));
 this.dataGridView1.AlternatingRowsDefaultCellStyle = dataGridViewCellStyle1;
 this.dataGridView1.AutoGenerateColumns = false;
 this.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize;
 this.dataGridView1.Columns.AddRange(new System.Windows.Forms.DataGridViewColumn[] {
 this.nameDataGridViewTextBoxColumn,
 this.salaryDataGridViewTextBoxColumn,
 this.iDDataGridViewTextBoxColumn});
 this.dataGridView1.DataSource = this.employeeListSource1;
 this.dataGridView1.Dock = System.Windows.Forms.DockStyle.Fill;
 this.dataGridView1.Location = new System.Drawing.Point(0, 51);
 this.dataGridView1.Name = "dataGridView1";
 this.dataGridView1.RowHeadersVisible = false;
 this.dataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
 this.dataGridView1.Size = new System.Drawing.Size(416, 215);
 this.dataGridView1.TabIndex = 12;
 //
 // nameDataGridViewTextBoxColumn
 //
 this.nameDataGridViewTextBoxColumn.DataPropertyName = "Name";
 this.nameDataGridViewTextBoxColumn.FillWeight = 131.7987F;
 this.nameDataGridViewTextBoxColumn.HeaderText = "Name";
 this.nameDataGridViewTextBoxColumn.Name = "nameDataGridViewTextBoxColumn";
 //
 // salaryDataGridViewTextBoxColumn
 //
 this.salaryDataGridViewTextBoxColumn.DataPropertyName = "ParkingID";
 this.salaryDataGridViewTextBoxColumn.DefaultCellStyle = dataGridViewCellStyle2;
 this.salaryDataGridViewTextBoxColumn.FillWeight = 121.8274F;
 this.salaryDataGridViewTextBoxColumn.HeaderText = "Parking ID";
 this.salaryDataGridViewTextBoxColumn.Name = "salaryDataGridViewTextBoxColumn";
 //
 // iDDataGridViewTextBoxColumn
 //
 this.iDDataGridViewTextBoxColumn.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.Fill;
 this.iDDataGridViewTextBoxColumn.DataPropertyName = "ID";
 this.iDDataGridViewTextBoxColumn.FillWeight = 46.37391F;
 this.iDDataGridViewTextBoxColumn.HeaderText = "ID";
 this.iDDataGridViewTextBoxColumn.Name = "iDDataGridViewTextBoxColumn";
 this.iDDataGridViewTextBoxColumn.ReadOnly = true;
 //
 // Form1
 //
 this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
 this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
 this.ClientSize = new System.Drawing.Size(416, 266);
 this.Controls.Add(this.dataGridView1);
 this.Controls.Add(this.flowLayoutPanel1);
 this.Name = "Form1";
 this.Text = "IListSource Sample";
 this.flowLayoutPanel1.ResumeLayout(false);
 this.flowLayoutPanel1.PerformLayout();
 ((System.ComponentModel.ISupportInitialize)(this.dataGridView1)).EndInit();
 this.ResumeLayout(false);
 this.PerformLayout();
 }

 #endregion
 }

 static class Program
 {
 [STAThread]
 static void Main()
 {
 Application.EnableVisualStyles();
 Application.SetCompatibleTextRenderingDefault(false);
 Application.Run(new Form1());
 }
 }
}

Imports System.ComponentModel
Imports System.Windows.Forms

Public Class Form1
 Inherits System.Windows.Forms.Form

 Friend WithEvents flowLayoutPanel1 As FlowLayoutPanel
 Friend WithEvents label2 As Label
 Friend WithEvents dataGridView1 As DataGridView
 Friend WithEvents nameDataGridViewTextBoxColumn As DataGridViewTextBoxColumn
 Friend WithEvents salaryDataGridViewTextBoxColumn As DataGridViewTextBoxColumn
 Friend WithEvents iDDataGridViewTextBoxColumn As DataGridViewTextBoxColumn
 Friend WithEvents employeeListSource1 As EmployeeListSource

 Public Sub New()
 MyBase.New()

 Me.InitializeComponent()
 End Sub

 'Form 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 Windows Form Designer
 Private components As System.ComponentModel.IContainer

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

 Dim dataGridViewCellStyle1 = New System.Windows.Forms.DataGridViewCellStyle()
 Dim dataGridViewCellStyle2 = New System.Windows.Forms.DataGridViewCellStyle()
 Me.flowLayoutPanel1 = New System.Windows.Forms.FlowLayoutPanel()
 Me.label2 = New System.Windows.Forms.Label()
 Me.dataGridView1 = New System.Windows.Forms.DataGridView()
 Me.nameDataGridViewTextBoxColumn = New System.Windows.Forms.DataGridViewTextBoxColumn()
 Me.salaryDataGridViewTextBoxColumn = New System.Windows.Forms.DataGridViewTextBoxColumn()
 Me.iDDataGridViewTextBoxColumn = New System.Windows.Forms.DataGridViewTextBoxColumn()
 Me.employeeListSource1 = New EmployeeListSource(Me.components)
 Me.flowLayoutPanel1.SuspendLayout()
 CType(Me.dataGridView1, System.ComponentModel.ISupportInitialize).BeginInit()
 Me.SuspendLayout()
 ' 
 ' flowLayoutPanel1
 ' 
 Me.flowLayoutPanel1.AutoSize = True
 Me.flowLayoutPanel1.Controls.Add(Me.label2)
 Me.flowLayoutPanel1.Dock = System.Windows.Forms.DockStyle.Top
 Me.flowLayoutPanel1.Location = New System.Drawing.Point(0, 0)
 Me.flowLayoutPanel1.Name = "flowLayoutPanel1"
 Me.flowLayoutPanel1.Size = New System.Drawing.Size(416, 51)
 Me.flowLayoutPanel1.TabIndex = 11
 ' 
 ' label2
 ' 
 Me.label2.AutoSize = True
 Me.label2.Location = New System.Drawing.Point(3, 6)
 Me.label2.Margin = New System.Windows.Forms.Padding(3, 6, 3, 6)
 Me.label2.Name = "label2"
 Me.label2.Size = New System.Drawing.Size(408, 39)
 Me.label2.TabIndex = 0
 Me.label2.Text = "This sample demonstrates how to implement the IListSource interface. In this sam" + _
 "ple, a DataGridView is bound at design time to a Component (employeeListSource1)" + _
 " that implements IListSource."
 ' 
 ' dataGridView1
 ' 
 Me.dataGridView1.AllowUserToAddRows = False
 Me.dataGridView1.AllowUserToDeleteRows = False
 dataGridViewCellStyle1.BackColor = System.Drawing.Color.FromArgb(255, 255, 192)
 Me.dataGridView1.AlternatingRowsDefaultCellStyle = dataGridViewCellStyle1
 Me.dataGridView1.AutoGenerateColumns = False
 Me.dataGridView1.ColumnHeadersHeightSizeMode = System.Windows.Forms.DataGridViewColumnHeadersHeightSizeMode.AutoSize
 Me.dataGridView1.Columns.AddRange(New System.Windows.Forms.DataGridViewColumn() { _
 Me.nameDataGridViewTextBoxColumn, Me.salaryDataGridViewTextBoxColumn, Me.iDDataGridViewTextBoxColumn})
 Me.dataGridView1.DataSource = Me.employeeListSource1
 Me.dataGridView1.Dock = System.Windows.Forms.DockStyle.Fill
 Me.dataGridView1.Location = New System.Drawing.Point(0, 51)
 Me.dataGridView1.Name = "dataGridView1"
 Me.dataGridView1.RowHeadersVisible = False
 Me.dataGridView1.SelectionMode = System.Windows.Forms.DataGridViewSelectionMode.FullRowSelect
 Me.dataGridView1.Size = New System.Drawing.Size(416, 215)
 Me.dataGridView1.TabIndex = 12
 ' 
 ' nameDataGridViewTextBoxColumn
 ' 
 Me.nameDataGridViewTextBoxColumn.DataPropertyName = "Name"
 Me.nameDataGridViewTextBoxColumn.FillWeight = 131.7987F
 Me.nameDataGridViewTextBoxColumn.HeaderText = "Name"
 Me.nameDataGridViewTextBoxColumn.Name = "nameDataGridViewTextBoxColumn"
 ' 
 ' salaryDataGridViewTextBoxColumn
 ' 
 Me.salaryDataGridViewTextBoxColumn.DataPropertyName = "ParkingID"
 Me.salaryDataGridViewTextBoxColumn.DefaultCellStyle = dataGridViewCellStyle2
 Me.salaryDataGridViewTextBoxColumn.FillWeight = 121.8274F
 Me.salaryDataGridViewTextBoxColumn.HeaderText = "Parking ID"
 Me.salaryDataGridViewTextBoxColumn.Name = "salaryDataGridViewTextBoxColumn"
 ' 
 ' iDDataGridViewTextBoxColumn
 ' 
 Me.iDDataGridViewTextBoxColumn.AutoSizeMode = System.Windows.Forms.DataGridViewAutoSizeColumnMode.Fill
 Me.iDDataGridViewTextBoxColumn.DataPropertyName = "ID"
 Me.iDDataGridViewTextBoxColumn.FillWeight = 46.37391F
 Me.iDDataGridViewTextBoxColumn.HeaderText = "ID"
 Me.iDDataGridViewTextBoxColumn.Name = "iDDataGridViewTextBoxColumn"
 Me.iDDataGridViewTextBoxColumn.ReadOnly = True
 ' 
 ' Form1
 ' 
 Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0F, 13.0F)
 Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
 Me.ClientSize = New System.Drawing.Size(416, 266)
 Me.Controls.Add(Me.dataGridView1)
 Me.Controls.Add(Me.flowLayoutPanel1)
 Me.Name = "Form1"
 Me.Text = "IListSource Sample"
 Me.flowLayoutPanel1.ResumeLayout(False)
 Me.flowLayoutPanel1.PerformLayout()
 CType(Me.dataGridView1, System.ComponentModel.ISupportInitialize).EndInit()
 Me.ResumeLayout(False)
 Me.PerformLayout()

 End Sub

 Shared Sub Main()
 Application.Run(New Form1())
 End Sub
End Class

Compiling the Code

This example requires:

References to the System.Drawing and System.Windows.Forms assemblies.

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Last updated on

URL: https://learn.microsoft.com/en-us/dotnet/desktop/winforms/how-to-implement-the-ilistsource-interface?view=netframeworkdesktop-4.8

⇱ How to: Implement the IListSource Interface - Windows Forms | Microsoft Learn

How to: Implement the IListSource Interface

Example

Compiling the Code

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