Collapses the current pane in a backward direction, and occupies its space by maximizing the next adjacent pane.
true, if the current pane has been collapsed successfully; otherwise, false.
Use the CollapseBackward method to collapse the current pane in a backward direction: from right to left for vertical panes, and from bottom to top for horizontal panes. Note, if the right-to-left feature is enabled for the control, the horizontal pane direction is reversed.
This method is not in effect for the last pane within a SplitterPaneCollection.