DataGridView.AutoGenerateColumns Propiedad

Definición

Obtiene o establece un valor que indica si se crean columnas automáticamente cuando se establece la propiedad DataSource o DataMember.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

Valor de propiedad

Es true si se crean columnas automáticamente; en caso contrario, es false.true if the columns should be created automatically; otherwise, false. De manera predeterminada, es true.The default is true.

Atributos

Ejemplos

En el ejemplo de código siguiente se muestra cómo agregar columnas manualmente y cómo enlazarlas a un origen de datos cuando se establece AutoGenerateColumns en false.The following code example demonstrates how to add columns manually and bind them to a data source when you set AutoGenerateColumns to false. En este ejemplo, un control DataGridView se enlaza a una lista de objetos de negocio Task.In this example, a DataGridView control is bound to a list of Task business objects. A continuación, se agregan las columnas y se enlazan a las propiedades Task a través de la propiedad DataGridViewColumn.DataPropertyName.Then, columns are added and are bound to Task properties through the DataGridViewColumn.DataPropertyName property. Este ejemplo forma parte de un ejemplo más grande disponible en [How para: Obtener acceso a los objetos de una Windows Forms lista desplegable DataGridViewComboBoxCell @ no__t-0.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

Comentarios

Las columnas se generan automáticamente cuando esta propiedad se establece en true y se establecen o cambian las propiedades DataSource o DataMember.Columns are automatically generated when this property is set to true and the DataSource or DataMember properties are set or changed. Las columnas también se pueden generar automáticamente cuando se cambia la propiedad AutoGenerateColumns de false a true.Columns can also be automatically generated when the AutoGenerateColumns property is changed from false to true. Si esta propiedad es true y el DataSource cambia, por lo que hay columnas que no coinciden con las columnas del valor DataSource anterior, se descartan los datos de las columnas no coincidentes.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. Esta propiedad se omite si no se establecen las propiedades DataSource o DataMember.This property is ignored if the DataSource or DataMember properties are not set.

Cuando AutoGenerateColumns se establece en true, el control DataGridView genera una columna por cada propiedad pública de los objetos en el origen de datos.When AutoGenerateColumns is set to true, the DataGridView control generates one column for each public property of the objects in the data source. Si los objetos enlazados implementan la interfaz ICustomTypeDescriptor, el control genera una columna por cada propiedad devuelta por el método GetProperties.If the bound objects implement the ICustomTypeDescriptor interface, the control generates one column for each property returned by the GetProperties method. Cada encabezado de columna contendrá el valor del nombre de propiedad que representa la columna.Each column header will contain the value of the property name the column represents.

Si establece la propiedad DataSource pero establece AutoGenerateColumns en false, debe agregar las columnas manualmente.If you set the DataSource property but set AutoGenerateColumns to false, you must add columns manually. Puede enlazar cada columna agregada al origen de datos estableciendo la propiedad DataGridViewColumn.DataPropertyName en el nombre de una propiedad expuesta por los objetos enlazados.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.

Nota

Al establecer el valor de DataSource en el Diseñador de Windows Forms se establece automáticamente la propiedad AutoGenerateColumns en false y se genera código para agregar y enlazar una columna para cada propiedad del origen de datos.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. El código que se genera en tiempo de diseño es equivalente al código agregado manualmente que se muestra en el ejemplo siguiente.The code that is generated at design-time is equivalent to the manually added code shown in the following example. No es lo mismo que la generación automática de columnas en tiempo de ejecución que se produce cuando la propiedad AutoGenerateColumns está establecida en 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.

Se aplica a

Consulte también: