Procédure : lier un contrôle Windows Forms à un typeHow to: Bind a Windows Forms Control to a Type

Quand vous créez des contrôles qui interagissent avec des données, vous devez parfois lier un contrôle à un type plutôt qu'à un objet.When you are building controls that interact with data, you will sometimes find it necessary to bind a control to a type, rather than an object. Cette situation se présente surtout au moment du design, quand les données peuvent ne pas être disponibles mais que vos contrôles liés aux données ont quand même besoin d'afficher des informations à partir de l'interface publique d'un type.This situation arises especially at design time, when data may not be available, but your data-bound controls still need to display information from a type's public interface. Par exemple, vous pouvez lier un contrôle DataGridView à un objet exposé par un service web et vouloir que le contrôle DataGridView étiquette ses colonnes au moment du design avec les noms de membres d'un type personnalisé.For example, you may bind a DataGridView control to an object exposed by a Web service and want the DataGridView control to label its columns at design time with the member names of a custom type.

Vous pouvez facilement lier un contrôle à un type avec le composant BindingSource.You can easily bind a control to a type with the BindingSource component.

ExempleExample

L'exemple de code suivant montre comment lier un contrôle DataGridView à un type personnalisé à l'aide d'un composant BindingSource.The following code example demonstrates how to bind a DataGridView control to a custom type by using a BindingSource component. Lors de l'exécution de l'exemple, vous remarquerez que le DataGridView a étiqueté les colonnes qui reflètent les propriétés d'un objet Customer, avant que le contrôle soit rempli avec des données.When you run the example, you'll notice the DataGridView has labeled columns that reflect the properties of a Customer object, before the control is populated with data. L'exemple comporte un bouton Add Customer pour ajouter des données au contrôle DataGridView.The example has an Add Customer button to add data to the DataGridView control. Quand vous cliquez sur le bouton, un nouvel objet Customer est ajouté à BindingSource.When you click the button, a new Customer object is added to the BindingSource. Dans un scénario réel, les données peuvent être obtenues par un appel à un service web ou autre source de données.In a real-world scenario, the data might be obtained by a call to a Web service or other data source.

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

class Form1 : Form
{
    BindingSource bSource = new BindingSource();
    private Button button1;
    DataGridView dgv = new DataGridView();

    public Form1()
    {
        this.button1 = new System.Windows.Forms.Button();
        this.button1.Location = new System.Drawing.Point(140, 326);
        this.button1.Name = "button1";
        this.button1.AutoSize = true;
        this.button1.Text = "Add Customer";
        this.button1.Click += new System.EventHandler(this.button1_Click);
        this.ClientSize = new System.Drawing.Size(362, 370);
        this.Controls.Add(this.button1);

        // Bind the BindingSource to the DemoCustomer type.
        bSource.DataSource = typeof(DemoCustomer);

        // Set up the DataGridView control.
        dgv.Dock = DockStyle.Top;
        this.Controls.Add(dgv);

        // Bind the DataGridView control to the BindingSource.
        dgv.DataSource = bSource;
       
    }
    public static void Main()
    {
        Application.Run(new Form1());
     
    }

    private void button1_Click(object sender, EventArgs e)
    {
        bSource.Add(new DemoCustomer(DateTime.Today));
    }
}

// This simple class is used to demonstrate binding to a type.
public class DemoCustomer
{
    public DemoCustomer()
    {
        idValue = Guid.NewGuid();
    }

    public DemoCustomer(DateTime FirstOrderDate)
    {
        FirstOrder = FirstOrderDate;
        idValue = Guid.NewGuid();
    }
    // These fields hold the data that backs the public properties.
    private DateTime firstOrderDateValue;
    private Guid idValue;
    private string custNameValue;

    public string CustomerName
    {
        get { return custNameValue; }
        set { custNameValue = value; }
    }
    
    // This is a property that represents a birth date.
    public DateTime FirstOrder
    {
        get
        {
            return this.firstOrderDateValue;
        }
        set
        {
            if (value != this.firstOrderDateValue)
            {
                this.firstOrderDateValue = value;
            }
        }
    }

    // This is a property that represents a customer ID.
    public Guid ID
    {
        get
        {
            return this.idValue;
        }
    }
}
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Windows.Forms

Class Form1
    Inherits Form
    Private bSource As New BindingSource()
    Private WithEvents button1 As Button
    Private dgv As New DataGridView()

    Public Sub New()
        Me.button1 = New System.Windows.Forms.Button()
        Me.button1.Location = New System.Drawing.Point(140, 326)
        Me.button1.Name = "button1"
        Me.button1.AutoSize = True
        Me.button1.Text = "Add Customer"
        Me.ClientSize = New System.Drawing.Size(362, 370)
        Me.Controls.Add(Me.button1)

        ' Bind the BindingSource to the DemoCustomer type.
        bSource.DataSource = GetType(DemoCustomer)

        ' Set up the DataGridView control.
        dgv.Dock = DockStyle.Top
        Me.Controls.Add(dgv)

        ' Bind the DataGridView control to the BindingSource.
        dgv.DataSource = bSource

    End Sub

    Public Shared Sub Main()
        Application.Run(New Form1())

    End Sub

    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
        Handles button1.Click
        bSource.Add(New DemoCustomer(DateTime.Today))

    End Sub
End Class

' This simple class is used to demonstrate binding to a type.
Public Class DemoCustomer

    Public Sub New()
        idValue = Guid.NewGuid()
    End Sub

    Public Sub New(ByVal FirstOrderDate As DateTime)
        FirstOrder = FirstOrderDate
        idValue = Guid.NewGuid()
    End Sub

    ' These fields hold the data that backs the public properties.
    Private firstOrderDateValue As DateTime
    Private idValue As Guid
    Private custNameValue As String

    Public Property CustomerName() As String
        Get
            Return custNameValue
        End Get
        Set(ByVal value As String)
            custNameValue = value
        End Set
    End Property

    ' This is a property that represents the first order date.
    Public Property FirstOrder() As DateTime
        Get
            Return Me.firstOrderDateValue
        End Get
        Set(ByVal value As DateTime)
            If value <> Me.firstOrderDateValue Then
                Me.firstOrderDateValue = value
            End If
        End Set
    End Property

    ' This is a property that represents a customer ID.
    Public ReadOnly Property ID() As Guid
        Get
            Return Me.idValue
        End Get
    End Property
End Class

Compilation du codeCompiling the Code

Cet exemple nécessite :This example requires:

  • des références aux assemblys System et System.Windows.Forms ;References to the System and System.Windows.Forms assemblies.

Voir aussiSee also