Count the number of visible rows in a DataGrid

Question

I would like to know how many rows are actually displayed by a WPF DataGrid.

I tried looping over DataGridRow and checking IsVisible, but it seems that rows report IsVisible = true even when they are not in the DataGrid viewport.

How can I count the number of visible rows correctly?

Answer 1

I've asked this question also on MSDN forum and got a good answer:

private bool IsUserVisible(FrameworkElement element, FrameworkElement container) {
    if (!element.IsVisible)
        return false;
    Rect bounds = element.TransformToAncestor(container).TransformBounds(new Rect(0.0, 0.0, element.ActualWidth, element.ActualHeight));
    Rect rect = new Rect(0.0, 0.0, container.ActualWidth, container.ActualHeight);
    return rect.Contains(bounds.TopLeft) || rect.Contains(bounds.BottomRight);
}