How to resize WPF DataGrid to fit its content?

Question

The aim

I would like to set such size for the DataGrid (standard, from WPF) so all cells (text) would be fully visible. I have window with DockPanel, with DataGrid

Answer 1

In my case, I found DataGrid use HorizontalAlignment="Stretch" VerticalAlignment="Stretch" in default, So I set it to

Then works.