DataGridView.AutoGenerateColumns Propriété

Définition

Obtient ou définit une valeur indiquant si les colonnes sont créées automatiquement lorsque les propriétés DataSource ou DataMember sont définies.Gets or sets a value indicating whether columns are created automatically when the DataSource or DataMember properties are set.

public:
 property bool AutoGenerateColumns { bool get(); void set(bool value); };
[System.ComponentModel.Browsable(false)]
public bool AutoGenerateColumns { get; set; }
member this.AutoGenerateColumns : bool with get, set
Public Property AutoGenerateColumns As Boolean

Valeur de propriété

true si les colonnes doivent être créées automatiquement ; sinon, false.true if the columns should be created automatically; otherwise, false. La valeur par défaut est true.The default is true.

Attributs

Exemples

L’exemple de code suivant montre comment ajouter manuellement des colonnes et les lier à une source de données lorsque vous affectez la valeur AutoGenerateColumns à false.The following code example demonstrates how to add columns manually and bind them to a data source when you set AutoGenerateColumns to false. Dans cet exemple, un contrôle DataGridView est lié à une liste d’objets métier Task.In this example, a DataGridView control is bound to a list of Task business objects. Ensuite, les colonnes sont ajoutées et sont liées aux propriétés Task par le biais de la propriété DataGridViewColumn.DataPropertyName.Then, columns are added and are bound to Task properties through the DataGridViewColumn.DataPropertyName property. Cet exemple fait partie d’un exemple plus complet disponible dans How à : Accédez aux objets dans une liste déroulante Windows Forms DataGridViewComboBoxCell.This example is part of a larger example available in How to: Access Objects in a Windows Forms DataGridViewComboBoxCell Drop-Down List.

public class Form1 : Form
{
    private List<Employee> employees = new List<Employee>();
    private List<Task> tasks = new List<Task>();
    private Button reportButton = new Button();
    private DataGridView dataGridView1 = new DataGridView();

    [STAThread]
    public static void Main()
    {
        Application.Run(new Form1());
    }

    public Form1()
    {
        dataGridView1.Dock = DockStyle.Fill;
        dataGridView1.AutoSizeColumnsMode = 
            DataGridViewAutoSizeColumnsMode.AllCells;
        reportButton.Text = "Generate Report";
        reportButton.Dock = DockStyle.Top;
        reportButton.Click += new EventHandler(reportButton_Click);

        Controls.Add(dataGridView1);
        Controls.Add(reportButton);
        Load += new EventHandler(Form1_Load);
        Text = "DataGridViewComboBoxColumn Demo";
    }

    // Initializes the data source and populates the DataGridView control.
    private void Form1_Load(object sender, EventArgs e)
    {
        PopulateLists();
        dataGridView1.AutoGenerateColumns = false;
        dataGridView1.DataSource = tasks;
        AddColumns();
    }

    // Populates the employees and tasks lists. 
    private void PopulateLists()
    {
        employees.Add(new Employee("Harry"));
        employees.Add(new Employee("Sally"));
        employees.Add(new Employee("Roy"));
        employees.Add(new Employee("Pris"));
        tasks.Add(new Task(1, employees[1]));
        tasks.Add(new Task(2));
        tasks.Add(new Task(3, employees[2]));
        tasks.Add(new Task(4));
    }

    // Configures columns for the DataGridView control.
    private void AddColumns()
    {
        DataGridViewTextBoxColumn idColumn = 
            new DataGridViewTextBoxColumn();
        idColumn.Name = "Task";
        idColumn.DataPropertyName = "Id";
        idColumn.ReadOnly = true;

        DataGridViewComboBoxColumn assignedToColumn = 
            new DataGridViewComboBoxColumn();

        // Populate the combo box drop-down list with Employee objects. 
        foreach (Employee e in employees) assignedToColumn.Items.Add(e);

        // Add "unassigned" to the drop-down list and display it for 
        // empty AssignedTo values or when the user presses CTRL+0. 
        assignedToColumn.Items.Add("unassigned");
        assignedToColumn.DefaultCellStyle.NullValue = "unassigned";

        assignedToColumn.Name = "Assigned To";
        assignedToColumn.DataPropertyName = "AssignedTo";
        assignedToColumn.AutoComplete = true;
        assignedToColumn.DisplayMember = "Name";
        assignedToColumn.ValueMember = "Self";

        // Add a button column. 
        DataGridViewButtonColumn buttonColumn = 
            new DataGridViewButtonColumn();
        buttonColumn.HeaderText = "";
        buttonColumn.Name = "Status Request";
        buttonColumn.Text = "Request Status";
        buttonColumn.UseColumnTextForButtonValue = true;

        dataGridView1.Columns.Add(idColumn);
        dataGridView1.Columns.Add(assignedToColumn);
        dataGridView1.Columns.Add(buttonColumn);

        // Add a CellClick handler to handle clicks in the button column.
        dataGridView1.CellClick +=
            new DataGridViewCellEventHandler(dataGridView1_CellClick);
    }

    // Reports on task assignments. 
    private void reportButton_Click(object sender, EventArgs e)
    {
        StringBuilder report = new StringBuilder();
        foreach (Task t in tasks)
        {
            String assignment = 
                t.AssignedTo == null ? 
                "unassigned" : "assigned to " + t.AssignedTo.Name;
            report.AppendFormat("Task {0} is {1}.", t.Id, assignment);
            report.Append(Environment.NewLine);
        }
        MessageBox.Show(report.ToString(), "Task Assignments");
    }

    // Calls the Employee.RequestStatus method.
    void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
    {
        // Ignore clicks that are not on button cells. 
        if (e.RowIndex < 0 || e.ColumnIndex !=
            dataGridView1.Columns["Status Request"].Index) return;

        // Retrieve the task ID.
        Int32 taskID = (Int32)dataGridView1[0, e.RowIndex].Value;

        // Retrieve the Employee object from the "Assigned To" cell.
        Employee assignedTo = dataGridView1.Rows[e.RowIndex]
            .Cells["Assigned To"].Value as Employee;

        // Request status through the Employee object if present. 
        if (assignedTo != null)
        {
            assignedTo.RequestStatus(taskID);
        }
        else
        {
            MessageBox.Show(String.Format(
                "Task {0} is unassigned.", taskID), "Status Request");
        }
    }

}
Public Class Form1
    Inherits Form

    Private employees As New List(Of Employee)
    Private tasks As New List(Of Task)
    Private WithEvents reportButton As New Button
    Private WithEvents dataGridView1 As New DataGridView

    <STAThread()> _
    Public Sub Main()
        Application.Run(New Form1)
    End Sub

    Sub New()
        dataGridView1.Dock = DockStyle.Fill
        dataGridView1.AutoSizeColumnsMode = _
            DataGridViewAutoSizeColumnsMode.AllCells
        reportButton.Text = "Generate Report"
        reportButton.Dock = DockStyle.Top

        Controls.Add(dataGridView1)
        Controls.Add(reportButton)
        Text = "DataGridViewComboBoxColumn Demo"
    End Sub

    ' Initializes the data source and populates the DataGridView control.
    Private Sub Form1_Load(ByVal sender As Object, _
        ByVal e As EventArgs) Handles Me.Load

        PopulateLists()
        dataGridView1.AutoGenerateColumns = False
        dataGridView1.DataSource = tasks
        AddColumns()

    End Sub

    ' Populates the employees and tasks lists. 
    Private Sub PopulateLists()
        employees.Add(New Employee("Harry"))
        employees.Add(New Employee("Sally"))
        employees.Add(New Employee("Roy"))
        employees.Add(New Employee("Pris"))
        tasks.Add(New Task(1, employees(1)))
        tasks.Add(New Task(2))
        tasks.Add(New Task(3, employees(2)))
        tasks.Add(New Task(4))
    End Sub

    ' Configures columns for the DataGridView control.
    Private Sub AddColumns()

        Dim idColumn As New DataGridViewTextBoxColumn()
        idColumn.Name = "Task"
        idColumn.DataPropertyName = "Id"
        idColumn.ReadOnly = True

        Dim assignedToColumn As New DataGridViewComboBoxColumn()

        ' Populate the combo box drop-down list with Employee objects. 
        For Each e As Employee In employees
            assignedToColumn.Items.Add(e)
        Next

        ' Add "unassigned" to the drop-down list and display it for 
        ' empty AssignedTo values or when the user presses CTRL+0. 
        assignedToColumn.Items.Add("unassigned")
        assignedToColumn.DefaultCellStyle.NullValue = "unassigned"

        assignedToColumn.Name = "Assigned To"
        assignedToColumn.DataPropertyName = "AssignedTo"
        assignedToColumn.AutoComplete = True
        assignedToColumn.DisplayMember = "Name"
        assignedToColumn.ValueMember = "Self"

        ' Add a button column. 
        Dim buttonColumn As New DataGridViewButtonColumn()
        buttonColumn.HeaderText = ""
        buttonColumn.Name = "Status Request"
        buttonColumn.Text = "Request Status"
        buttonColumn.UseColumnTextForButtonValue = True

        dataGridView1.Columns.Add(idColumn)
        dataGridView1.Columns.Add(assignedToColumn)
        dataGridView1.Columns.Add(buttonColumn)

    End Sub

    ' Reports on task assignments. 
    Private Sub reportButton_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles reportButton.Click

        Dim report As New StringBuilder()
        For Each t As Task In tasks
            Dim assignment As String
            If t.AssignedTo Is Nothing Then
                assignment = "unassigned"
            Else
                assignment = "assigned to " + t.AssignedTo.Name
            End If
            report.AppendFormat("Task {0} is {1}.", t.Id, assignment)
            report.Append(Environment.NewLine)
        Next
        MessageBox.Show(report.ToString(), "Task Assignments")

    End Sub

    ' Calls the Employee.RequestStatus method.
    Private Sub dataGridView1_CellClick(ByVal sender As Object, _
        ByVal e As DataGridViewCellEventArgs) _
        Handles dataGridView1.CellClick

        ' Ignore clicks that are not on button cells. 
        If e.RowIndex < 0 OrElse Not e.ColumnIndex = _
            dataGridView1.Columns("Status Request").Index Then Return

        ' Retrieve the task ID.
        Dim taskID As Int32 = CInt(dataGridView1(0, e.RowIndex).Value)

        ' Retrieve the Employee object from the "Assigned To" cell.
        Dim assignedTo As Employee = TryCast(dataGridView1.Rows(e.RowIndex) _
            .Cells("Assigned To").Value, Employee)

        ' Request status through the Employee object if present. 
        If assignedTo IsNot Nothing Then
            assignedTo.RequestStatus(taskID)
        Else
            MessageBox.Show(String.Format( _
                "Task {0} is unassigned.", taskID), "Status Request")
        End If

    End Sub

End Class

Remarques

Les colonnes sont générées automatiquement lorsque cette propriété a la valeur true et que les propriétés DataSource ou DataMember sont définies ou modifiées.Columns are automatically generated when this property is set to true and the DataSource or DataMember properties are set or changed. Les colonnes peuvent également être générées automatiquement lorsque la propriété AutoGenerateColumns passe de false à true.Columns can also be automatically generated when the AutoGenerateColumns property is changed from false to true. Si cette propriété a la valeur true et que les modifications apportées à DataSource correspondent à des colonnes qui ne correspondent pas aux colonnes de la valeur DataSource précédente, les données des colonnes non appariées sont ignorées.If this property is true and the DataSource changes so there are columns that do not match the columns of the previous DataSource value, data in the unmatched columns is discarded. Cette propriété est ignorée si les propriétés DataSource ou DataMember ne sont pas définies.This property is ignored if the DataSource or DataMember properties are not set.

Lorsque AutoGenerateColumns a la valeur true, le contrôle DataGridView génère une colonne pour chaque propriété publique des objets dans la source de données.When AutoGenerateColumns is set to true, the DataGridView control generates one column for each public property of the objects in the data source. Si les objets liés implémentent l’interface ICustomTypeDescriptor, le contrôle génère une colonne pour chaque propriété retournée par la méthode GetProperties.If the bound objects implement the ICustomTypeDescriptor interface, the control generates one column for each property returned by the GetProperties method. Chaque en-tête de colonne contient la valeur du nom de propriété que la colonne représente.Each column header will contain the value of the property name the column represents.

Si vous définissez la propriété DataSource, mais que vous définissez AutoGenerateColumns sur false, vous devez ajouter manuellement des colonnes.If you set the DataSource property but set AutoGenerateColumns to false, you must add columns manually. Vous pouvez lier chaque colonne ajoutée à la source de données en affectant à la propriété DataGridViewColumn.DataPropertyName le nom d’une propriété exposée par les objets liés.You can bind each added column to the data source by setting the DataGridViewColumn.DataPropertyName property to the name of a property exposed by the bound objects.

Notes

La définition de la DataSource dans le Concepteur Windows Forms affecte automatiquement à la propriété AutoGenerateColumns la valeur false et génère du code pour ajouter et lier une colonne pour chaque propriété de la source de données.Setting the DataSource in the Windows Forms Designer automatically sets the AutoGenerateColumns property to false and generates code to add and bind a column for each property in the data source. Le code généré au moment de la conception est équivalent au code ajouté manuellement illustré dans l’exemple suivant.The code that is generated at design-time is equivalent to the manually added code shown in the following example. Ce n’est pas la même que la génération automatique de colonnes au moment de l’exécution qui se produit lorsque la propriété AutoGenerateColumns est définie sur true.It is not the same as the auto-generation of columns at run-time that occurs when the AutoGenerateColumns property is set to true.

S’applique à

Voir aussi