RowsAdded Event
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DataGridView.RowsAdded Event


Occurs after a new row is added to the DataGridView.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

Public Event RowsAdded As DataGridViewRowsAddedEventHandler

Rows in the control are not automatically sorted when new rows are added. To sort new rows into their correct position, call the Sort method in a RowsAdded event handler.

When the user adds a new row using the row for new records, the DataGridViewRowsAddedEventArgs.RowIndex value in the handler for this event is equal to the index of the new location of the row for new records, which is one greater than the row just added. When you add rows programmatically, however, the RowIndex value is the index of the first row added.

In virtual mode, this event occurs before the CellValuePushed event and can be used to create new records in your data store that you can then populate in the CellValuePushed event handler.

For more information about handling events, see NIB: Consuming Events.

The following code example handles the RowsAdded event to increment the number of rows in a virtual DataGridView. The number of rows is used in the CellValueNeeded handler so it knows when to show a blank cell versus an initialized cell for a new row. This example is part of a larger example available in the VirtualMode reference topic.

    Dim newRowNeeded As Boolean

    Private Sub dataGridView1_NewRowNeeded(ByVal sender As Object, _
        ByVal e As DataGridViewRowEventArgs) _
        Handles dataGridView1.NewRowNeeded

        newRowNeeded = True
    End Sub

    Const initialSize As Integer = 5000000
    Dim numberOfRows As Integer = initialSize

    Private Sub dataGridView1_RowsAdded(ByVal sender As Object, _
        ByVal e As DataGridViewRowsAddedEventArgs) _
        Handles dataGridView1.RowsAdded

        If newRowNeeded Then
            newRowNeeded = False
            numberOfRows = numberOfRows + 1
        End If
    End Sub

#Region "data store maintance"
    Const initialValue As Integer = -1

    Private Sub dataGridView1_CellValueNeeded(ByVal sender As Object, _
        ByVal e As DataGridViewCellValueEventArgs) _
        Handles dataGridView1.CellValueNeeded

        If store.ContainsKey(e.RowIndex) Then
            ' Use the store if the e value has been modified 
            ' and stored.
            e.Value = store(e.RowIndex)
        ElseIf newRowNeeded AndAlso e.RowIndex = numberOfRows Then
            If dataGridView1.IsCurrentCellInEditMode Then
                e.Value = initialValue
                ' Show a blank value if the cursor is just resting
                ' on the last row.
                e.Value = String.Empty
            End If
            e.Value = e.RowIndex
        End If
    End Sub

    Private Sub dataGridView1_CellValuePushed(ByVal sender As Object, _
        ByVal e As DataGridViewCellValueEventArgs) _
        Handles dataGridView1.CellValuePushed

        store.Add(e.RowIndex, CInt(e.Value))

    End Sub
#End Region

    Dim store As System.Collections.Generic.Dictionary(Of Integer, Integer) = _
        New Dictionary(Of Integer, Integer)

.NET Framework
Available since 2.0
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