DataGridViewCell.DefaultNewRowValue Proprietà

Definizione

Ottiene il valore predefinito per una cella nella riga per i nuovi record.Gets the default value for a cell in the row for new records.

public:
 virtual property System::Object ^ DefaultNewRowValue { System::Object ^ get(); };
[System.ComponentModel.Browsable(false)]
public virtual object DefaultNewRowValue { get; }
[<System.ComponentModel.Browsable(false)>]
member this.DefaultNewRowValue : obj
Public Overridable ReadOnly Property DefaultNewRowValue As Object

Valore della proprietà

Object

Classe Object che rappresenta il valore predefinito.An Object representing the default value.

Attributi

Esempio

Nell'esempio di codice riportato di seguito viene illustrato come eseguire l'override della DefaultNewRowValue Proprietà in una CalendarCell classe che deriva da DataGridViewTextBoxCell .The following code example demonstrates how to override the DefaultNewRowValue property in a CalendarCell class that derives from DataGridViewTextBoxCell. Questo esempio fa parte di un esempio di codice più ampio fornito in procedura: ospitare i controlli in Windows Form celle DataGridView.This example is part of a larger code example provided in How to: Host Controls in Windows Forms DataGridView Cells.

public class CalendarCell : DataGridViewTextBoxCell
{

    public CalendarCell()
        : base()
    {
        // Use the short date format.
        this.Style.Format = "d";
    }

    public override void InitializeEditingControl(int rowIndex, object 
        initialFormattedValue, DataGridViewCellStyle dataGridViewCellStyle)
    {
        // Set the value of the editing control to the current cell value.
        base.InitializeEditingControl(rowIndex, initialFormattedValue, 
            dataGridViewCellStyle);
        CalendarEditingControl ctl = 
            DataGridView.EditingControl as CalendarEditingControl;
        // Use the default row value when Value property is null.
        if (this.Value == null)
        {
            ctl.Value = (DateTime)this.DefaultNewRowValue;
        }
        else
        {
            ctl.Value = (DateTime)this.Value;
        }
    }

    public override Type EditType
    {
        get
        {
            // Return the type of the editing control that CalendarCell uses.
            return typeof(CalendarEditingControl);
        }
    }

    public override Type ValueType
    {
        get
        {
            // Return the type of the value that CalendarCell contains.
            
            return typeof(DateTime);
        }
    }

    public override object DefaultNewRowValue
    {
        get
        {
            // Use the current date and time as the default value.
            return DateTime.Now;
        }
    }
}
Public Class CalendarCell
    Inherits DataGridViewTextBoxCell

    Public Sub New()
        ' Use the short date format.
        Me.Style.Format = "d"
    End Sub

    Public Overrides Sub InitializeEditingControl(ByVal rowIndex As Integer, _
        ByVal initialFormattedValue As Object, _
        ByVal dataGridViewCellStyle As DataGridViewCellStyle)

        ' Set the value of the editing control to the current cell value.
        MyBase.InitializeEditingControl(rowIndex, initialFormattedValue, _
            dataGridViewCellStyle)

        Dim ctl As CalendarEditingControl = _
            CType(DataGridView.EditingControl, CalendarEditingControl)

        ' Use the default row value when Value property is null.
        If (Me.Value Is Nothing) Then
            ctl.Value = CType(Me.DefaultNewRowValue, DateTime)
        Else
            ctl.Value = CType(Me.Value, DateTime)
        End If
    End Sub

    Public Overrides ReadOnly Property EditType() As Type
        Get
            ' Return the type of the editing control that CalendarCell uses.
            Return GetType(CalendarEditingControl)
        End Get
    End Property

    Public Overrides ReadOnly Property ValueType() As Type
        Get
            ' Return the type of the value that CalendarCell contains.
            Return GetType(DateTime)
        End Get
    End Property

    Public Overrides ReadOnly Property DefaultNewRowValue() As Object
        Get
            ' Use the current date and time as the default value.
            Return DateTime.Now
        End Get
    End Property

End Class

Commenti

La DefaultNewRowValue proprietà nella classe di base DataGridViewCell restituisce sempre null .The DefaultNewRowValue property in the base class DataGridViewCell always returns null. Tuttavia, questa proprietà può essere sottoposta a override nelle classi di celle derivate per restituire altri valori predefiniti.However, this property can be overridden in derived cell classes to return other default values.

Il valore restituito da questa proprietà viene visualizzato se la cella si trova nella riga per i nuovi record.The value returned by this property is displayed if the cell is in the row for new records. Questo valore può essere sottoposto a override da un gestore per l' DataGridView.DefaultValuesNeeded evento quando lo stato attivo immette la riga per i nuovi record.This value can be overridden by a handler for the DataGridView.DefaultValuesNeeded event when focus enters the row for new records.

Si applica a

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