DataGridViewCell.DefaultNewRowValue DataGridViewCell.DefaultNewRowValue DataGridViewCell.DefaultNewRowValue DataGridViewCell.DefaultNewRowValue Property

定義

取得新資料錄之資料列中儲存格的預設值。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; }
member this.DefaultNewRowValue : obj
Public Overridable ReadOnly Property DefaultNewRowValue As Object

屬性值

Object,表示預設值。An Object representing the default value.

範例

下列程式碼範例示範如何DefaultNewRowValue CalendarCell在衍生自DataGridViewTextBoxCell的類別中覆寫屬性。The following code example demonstrates how to override the DefaultNewRowValue property in a CalendarCell class that derives from DataGridViewTextBoxCell. 這個範例是在如何:中提供的較大程式碼範例的一部分。Windows Forms DataGridView 儲存格中的主控制項。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

備註

基類中的DefaultNewRowValue屬性null一律會傳回。 DataGridViewCellThe DefaultNewRowValue property in the base class DataGridViewCell always returns null. 不過,您可以在衍生的資料格類別中覆寫這個屬性,以傳回其他預設值。However, this property can be overridden in derived cell classes to return other default values.

如果資料格是在新記錄的資料列中,就會顯示此屬性所傳回的值。The value returned by this property is displayed if the cell is in the row for new records. 當焦點進入新記錄的資料列時, DataGridView.DefaultValuesNeeded事件的處理常式可以覆寫這個值。This value can be overridden by a handler for the DataGridView.DefaultValuesNeeded event when focus enters the row for new records.

適用於

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