"WPF" perfect layout does not leave White: solve WrapPanel right white problem

Making full use of the space on the interface is one of the principles of excellent software interface layout design. If a large blank area appears on the layout, it will give a person a sense of waste and discord. As shown in the following figure.

We set the Itemspanel of the listbox to a wrappanel. So that the items inside can be automatically folded line. But then, on the right side of the ListBox, a blank area appears. In many cases, we don't really care about the size of the item, and we want the item's width to be automatically adjusted with the overall width. Produces the effect shown in the following figure.