Customizing FloatWindow

By Ryan Rastedt, Lex Li

This page shows you how to customize FloatWindow.

In this article:

Maximizable FloatWindow

Out of the box, a window that is undocked to a floating state lacks a maximize button. Utilizing the Extender functionality of DockPanel it’s easy to customize the FloatWindow class!

The first step is to create a custom class that extends FloatWindow. By default, FloatWindow has a FormBorderStyle of SizableToolWindow which will only provide a close button. To expose the maximize and minimize button, set FormBorderStyle of the custom window to Sizable,

public class CustomFloatWindow : FloatWindow
    public CustomFloatWindow(DockPanel dockPanel, DockPane pane)
        : base (dockPanel, pane)
        FormBorderStyle = FormBorderStyle.Sizable;

    public CustomFloatWindow(DockPanel dockPanel, DockPane pane, Rectangle bounds)
        : base (dockPanel, pane, bounds)
        FormBorderStyle = FormBorderStyle.Sizable;

Next, create a factory class to create the CustomFloatWindow. This is done by implementing the IFloatWindowFactory interface,

public class CustomFloatWindowFactory : DockPanelExtender.IFloatWindowFactory
    public FloatWindow CreateFloatWindow(DockPanel dockPanel, DockPane pane, Rectangle bounds)
        return new CustomFloatWindow(dockPanel, pane, bounds);

    public FloatWindow CreateFloatWindow(DockPanel dockPanel, DockPane pane)
        return new CustomFloatWindow(dockPanel, pane);

Lastly, attach the new factory to the DockPanel control,

this.dockPanel.Extender.FloatWindowFactory = new CustomFloatWindowFactory();

Alt+Tab Support

To enable Alt+Tab between your undocked forms and your main form add this to your CustomFloatWindow constructors,

ShowInTaskbar = true;
Owner = null;

Overriding Double Clicking Behavior


This requires DockPanel Suite version 2.8 and above.

By default, when a float window’s title bar is double clicked it is redocked into the DockPanel. This behavior can be disabled (and allow the Windows default behavior of maximizing/restoring the window) by setting the following property in your CustomFloatWindow constructor,

DoubleClickTitleBarToDock = false;

Positioning for Multiple Monitors

When a dock content is set to float, the created FloatWindow might be at a secondary monitor (depending on WinForms underlying positioning).

To force the FloatWindow to appear on a desired monitor, a custom FloatWindow can be created. Then override its SetBoundsCore method to check the monitors based on the information exposed by the Screen class.

Top-Most FloatWindow

To make the FloatWindow top-most, simply create a custom FloatWindow class and set its TopMost property to true.