DataGridView.RowsAdded Event
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Occurs after a new row is added to the DataGridView.
public:
event System::Windows::Forms::DataGridViewRowsAddedEventHandler ^ RowsAdded;public event System.Windows.Forms.DataGridViewRowsAddedEventHandler RowsAdded;public event System.Windows.Forms.DataGridViewRowsAddedEventHandler? RowsAdded;member this.RowsAdded : System.Windows.Forms.DataGridViewRowsAddedEventHandler Public Custom Event RowsAdded As DataGridViewRowsAddedEventHandler Event Type
Examples
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.
void VirtualConnector::dataGridView1_NewRowNeeded
(Object^ sender, DataGridViewRowEventArgs^ e)
{
newRowNeeded = true;
}
void VirtualConnector::dataGridView1_RowsAdded
(Object^ sender, DataGridViewRowsAddedEventArgs^ e)
{
if (newRowNeeded)
{
newRowNeeded = false;
numberOfRows = numberOfRows + 1;
}
}
#pragma region Data store maintance
void VirtualConnector::dataGridView1_CellValueNeeded
(Object^ sender, DataGridViewCellValueEventArgs^ e)
{
if (store->ContainsKey(e->RowIndex))
{
// Use the store if the e value has been modified
// and stored.
e->Value = gcnew Int32(store->default[e->RowIndex]);
}
else if (newRowNeeded && e->RowIndex == numberOfRows)
{
if (dataGridView1->IsCurrentCellInEditMode)
{
e->Value = initialValue;
}
else
{
// Show a blank e if the cursor is just loitering
// over(the) last row.
e->Value = String::Empty;
}
}
else
{
e->Value = e->RowIndex;
}
}
void VirtualConnector::dataGridView1_CellValuePushed
(Object^ sender, DataGridViewCellValueEventArgs^ e)
{
String^ value = e->Value->ToString();
store[e->RowIndex] = Int32::Parse(value,
CultureInfo::CurrentCulture);
}
#pragma endregion
bool newRowNeeded;
private void dataGridView1_NewRowNeeded(object sender,
DataGridViewRowEventArgs e)
{
newRowNeeded = true;
}
const int initialSize = 5000000;
int numberOfRows = initialSize;
private void dataGridView1_RowsAdded(object sender,
DataGridViewRowsAddedEventArgs e)
{
if (newRowNeeded)
{
newRowNeeded = false;
numberOfRows = numberOfRows + 1;
}
}
#region "data store maintance"
const int initialValue = -1;
private void dataGridView1_CellValueNeeded(object sender,
DataGridViewCellValueEventArgs e)
{
if (store.ContainsKey(e.RowIndex))
{
// Use the store if the e value has been modified
// and stored.
e.Value = store[e.RowIndex];
}
else if (newRowNeeded && e.RowIndex == numberOfRows)
{
if (dataGridView1.IsCurrentCellInEditMode)
{
e.Value = initialValue;
}
else
{
// Show a blank value if the cursor is just resting
// on the last row.
e.Value = String.Empty;
}
}
else
{
e.Value = e.RowIndex;
}
}
private void dataGridView1_CellValuePushed(object sender,
DataGridViewCellValueEventArgs e)
{
store.Add(e.RowIndex, int.Parse(e.Value.ToString()));
}
#endregion
private Dictionary<int, int> store = new Dictionary<int, int>();
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
Else
' Show a blank value if the cursor is just resting
' on the last row.
e.Value = String.Empty
End If
Else
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)
Remarks
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 how to handle events, see Handling and Raising Events.
