DataGridViewCell.DefaultNewRowValue 属性

定义

获取新记录所在行中单元格的默认值。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; }
[<System.ComponentModel.Browsable(false)>]
member this.DefaultNewRowValue : obj
Public Overridable ReadOnly Property DefaultNewRowValue As Object

属性值

Object

表示默认值的 ObjectAn Object representing the default value.

属性

示例

下面的代码示例演示如何 DefaultNewRowValue 在从派生的类中重写属性 CalendarCell DataGridViewTextBoxCellThe following code example demonstrates how to override the DefaultNewRowValue property in a CalendarCell class that derives from DataGridViewTextBoxCell. 此示例摘自 如何:在 Windows 窗体 DataGridView 单元格中承载控件中提供的一个更大的代码示例。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

注解

DefaultNewRowValue基类中的属性 DataGridViewCell 始终返回 nullThe DefaultNewRowValue property in the base class DataGridViewCell always returns null. 但是,可以在派生的单元类中重写此属性以返回其他默认值。However, this property can be overridden in derived cell classes to return other default values.

如果该单元格位于新记录的行中,则会显示此属性返回的值。The value returned by this property is displayed if the cell is in the row for new records. DataGridView.DefaultValuesNeeded当焦点进入新记录的行时,该事件的处理程序可以重写此值。This value can be overridden by a handler for the DataGridView.DefaultValuesNeeded event when focus enters the row for new records.

适用于

另请参阅