SplitContainer

SplitContainer is a Windows Forms control that provides a split view with two resizable panels separated by a movable splitter bar. It is commonly used to present two related areas, such as a navigation pane and a content pane, within a single window.

The control contains two panels, Panel1 and Panel2, inside one container. The Orientation property determines the split direction: Vertical creates left and right panels, while Horizontal creates top and bottom panels. The position of the splitter is controlled by SplitterDistance, and the width of the splitter bar is controlled by SplitterWidth. Each panel can host its own set of child controls, accessed via Panel1.Controls and Panel2.Controls.

Key properties and behavior include Panel1MinSize and Panel2MinSize for minimum panel sizes, FixedPanel to keep a specified panel fixed during resizing, and IsSplitterFixed to make the splitter non-movable. The SplitterMoved and SplitterMoving events allow monitoring or restricting user-driven splitter movement.

Usage typically involves adding a SplitContainer to a form, docking it (for example, Dock = Fill), and placing controls into the two panels as needed. It supports dynamic resizing within layouts and is commonly used to create adaptable interfaces where the relative sizes of the two areas matter.

SplitContainer is part of the System.Windows.Forms namespace in the .NET Windows Forms framework. It is distinct from similar controls in other platforms (for example, WPF uses GridSplitter for comparable functionality).