Disable button when selecting item in Datagrid

Question

I have a datagrid with records and an edit button. At the moment I am doing the following: the user selects the Datagrid item and clicks the Edit button, to then be performed the verification whether or not he can edit the record. I would like to disable the button as soon as the item was selected in Datagrid, without having to click the button to be warned that it cannot edit.

private void btnEditar_Click(object sender, RoutedEventArgs e)
    {
        if (dataGrid.SelectedItem != null)
        {
            if (Presenter.PodeEditar())
            {
                chamaMetodoEdicao();
            }
            else
                MessageBox.Show("Impossível editar!");
        }
        else
            MessageBox.Show("Selecione um item.");
    }

Answer 1

In Windows Forms you can use the event CellEnter(). This event is triggered whenever you click on a cell (when the cell receives focus).

Example:

private void dataGrid_CellEnter(object sender, DataGridViewCellEventArgs e)
{
    if (Presenter.PodeEditar())
       chamaMetodoEdicao();        
    else
        MessageBox.Show("Impossível editar!");
}

In the WPF, you can use the method SelectionChanged(). Just like the CellEnter() of Windows Forms the SelectionChanged() is fired whenever a cell is clicked.

Example:

private void DataGrid_SelectionChanged(object sender, EventArgs e)
{
    if (Presenter.PodeEditar())
        chamaMetodoEdicao();        
    else
        MessageBox.Show("Impossível editar!");
}