Hi

The best way is to subscribe for CollectionChanged event of pivot grid datasource for the area you are interested in. See example below.

public MainWindow()
{
    InitializeComponent();
    pivotGrid.DataSource.Columns.CollectionChanged += Columns_CollectionChanged;
    pivotGrid.DataSource.Rows.CollectionChanged += Rows_CollectionChanged;
    pivotGrid.DataSource.Measures.CollectionChanged += Measures_CollectionChanged;
    pivotGrid.DataSource.Filters.CollectionChanged += Filters_CollectionChanged;
}