DataGridView capturing user row selection

Question

I am having trouble handling the selections in DataGridView. My grid view contains an amount column. There is a textbox on the form which should display the total amount of the selected grid view rows. Hence I need to capture events when the user selects/ deselects the gridview rows and calculate (add/ subtract) the amount accordingly. I have found two methods of doing it:

1. Using the RowEnter and RowLeave events. These work fine when user selects/ deselects a single row. However, when the user is selecting multiple rows at one go, the event gets fired only for the last row. Hence, from my total amount only the amount in the last row gets added/ subtracted. Thus making my result erroneous.

2. Using the RowStateChanged event. This works for multiple rows. However, the event gets fired event if the user scrolls through the datagrid.

Has anyone handled such a scenario. I would like to know which datagrid event I should be using, so that my code executes only when user selects/ deselects rows including multiple rows.

Answer 1

Found the solution. I can use RowStateChanged and run my code only if StateChanged for the row is Selected...

private void dgridv_RowStateChanged(object sender, DataGridViewRowStateChangedEventArgs e)
{
    // For any other operation except, StateChanged, do nothing
    if (e.StateChanged != DataGridViewElementStates.Selected) return;

    // Calculate amount code goes here
}

Answer 2

I use SelectionChanged event or CellValueChanged event:

        dtGrid.SelectionChanged += DataGridView_SelectionChanged;
        this.dtGrid.DataSource = GetListOfEntities;
        dtGrid.CellValueChanged += DataGridView_CellValueChanged;


    private void DataGridView_CellValueChanged(object sender, DataGridViewCellEventArgs e)
    {
        DataGridViewRow row = dtGrid.Rows[e.RowIndex];
        SetRowProperties(row);
    }

    private void DataGridView_SelectionChanged(object sender, EventArgs e)
    {
        var rowsCount = dtGrid.SelectedRows.Count;
        if (rowsCount == 0 || rowsCount > 1) return;

        var row = dtGrid.SelectedRows[0];
        if (row == null) return; 
        ResolveActionsForRow(row);
    }

Answer 3

I think you can consider the SelectionChanged event:

private void DataGridView1_SelectionChanged(object sender, EventArgs e) {
  textbox1.Text = DataGridView1.SelectedRows.Count.ToString();
}