DataGridViewCellValidatingEventArgs Class

The DataGridView.CellValidating event lets you cancel changes to the current cell when the new value is not valid. Use the FormattedValue property to determine the current value. To determine the state of the current cell, use the RowIndex and ColumnIndex properties to access the cell through the DataGridView.Rows collection. To cancel the change, set the Cancel property to true.

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 DataGridView.CellValuePushed event will not be raised.

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.

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";
    }
}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference