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DataGridViewCellValidatingEventHandler Delegate

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll

Represents the method that will handle the CellValidating event of a DataGridView control.

public delegate void DataGridViewCellValidatingEventHandler(System::Object ^ sender, DataGridViewCellValidatingEventArgs ^ e);
public delegate void DataGridViewCellValidatingEventHandler(object sender, DataGridViewCellValidatingEventArgs e);
public delegate void DataGridViewCellValidatingEventHandler(object? sender, DataGridViewCellValidatingEventArgs e);
type DataGridViewCellValidatingEventHandler = delegate of obj * DataGridViewCellValidatingEventArgs -> unit
Public Delegate Sub DataGridViewCellValidatingEventHandler(sender As Object, e As DataGridViewCellValidatingEventArgs)

Parameters

sender
Object

A reference to the event sender.

e
DataGridViewCellValidatingEventArgs

A DataGridViewCellValidatingEventArgs that contains the event data.

Examples

The following code example handles the CellValidating event to ensure that only positive integers are entered by the user. This example is part of a larger example available in the VirtualMode reference topic.

void VirtualConnector::dataGridView1_CellValidating
    (Object^ sender, DataGridViewCellValidatingEventArgs^ e)
{
    int newInteger;

    // Don't try to validate the 'new row' until finished 
    // editing since there
    // is not any point in validating its initial value.
    if (dataGridView1->Rows[e->RowIndex]->IsNewRow) 
    {
        return; 
    }
    if (!Int32::TryParse(e->FormattedValue->ToString(), 
        newInteger) || (newInteger < 0))
    {
        e->Cancel = true;
    }
}

private void dataGridView1_CellValidating(object sender,
    DataGridViewCellValidatingEventArgs e)
{
    dataGridView1.Rows[e.RowIndex].ErrorText = "";
    int newInteger;

    // Don't try to validate the 'new row' until finished 
    // editing since there
    // is not any point in validating its initial value.
    if (dataGridView1.Rows[e.RowIndex].IsNewRow) { return; }
    if (!int.TryParse(e.FormattedValue.ToString(),
        out newInteger) || newInteger < 0)
    {
        e.Cancel = true;
        dataGridView1.Rows[e.RowIndex].ErrorText = "the value must be a non-negative integer";
    }
}

Private Sub dataGridView1_CellValidating(ByVal sender As Object, _
    ByVal e _
    As DataGridViewCellValidatingEventArgs) _
    Handles dataGridView1.CellValidating

    Me.dataGridView1.Rows(e.RowIndex).ErrorText = ""
    Dim newInteger As Integer

    ' Don't try to validate the 'new row' until finished 
    ' editing since there
    ' is not any point in validating its initial value.
    If dataGridView1.Rows(e.RowIndex).IsNewRow Then Return
    If Not Integer.TryParse(e.FormattedValue.ToString(), newInteger) _
        OrElse newInteger < 0 Then

        e.Cancel = True
        Me.dataGridView1.Rows(e.RowIndex).ErrorText = "the value must be a non-negative integer"

    End If
End Sub

Remarks

The CellValidating event occurs when a cell loses input focus, enabling content validation. Canceling this event cancels the changes to the current cell. When this event is canceled in data-bound mode, the new value is not pushed to the underlying data source. When this event is canceled in virtual mode, the CellValuePushed event will not be raised.

When you create a DataGridViewCellValidatingEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Handling and Raising Events.

Extension Methods

GetMethodInfo(Delegate)

Gets an object that represents the method represented by the specified delegate.

Applies to

See also