WPF 滚动自动调整大小面板

Question

I have a WPF application in which the main window holds a DockPanel with two children. The top child is another DockPanel which holds the menu and is of a fixed size. The lower child is the main work area, which should fill the remaining space and be resizable along with the window. (Hence the DockPanel parent.) Draggable objects get placed in this work area and might appear anywhere inside it.

I'm trying to figure out how to make scroll bars appear if an object is dragged outside the visible area. The approximate XAML structure currently goes

<Window> <DockPanel> <DockPanel with fixed-size content... > <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto"> <Grid ClipToBounds="True" VerticalAlignment="Stretch" HorizontalAlignment="Stretch"/> </ScrollViewer> </DockPanel> </Window>

So far I've tried a Grid and a Canvas. Both have built-in scroll bars, but they won't appear unless dimensions are specified--but if I apply dimensions, then the panel won't automatically resize to fill the work area. Then I tried surrounding the panel with a ScrollViewer. The unconstrained panel now successfully auto-resizes to fill the space, but the ScrollViewer has the same problem as the panel--it will only display scroll bars if it's constrained to hard dimensions.

I'm thinking that this would work if I could dynamically constrain the ScrollViewer. So far, I haven't found any reliable way to dynamically apply size values to the ScrollViewer. Is there a way to create a Binding between the ScrollViewer dimensions and the ActualHeight and ActualWidth of the Grid? Or, is there a way I can define the ActualHeight/ActualWidth of the grid as a DynamicResource that can be applied to the ScrollViewer? Or is there some other panel or method or resource that can be used so that all three criteria (panel fills available space, panel auto-resizes with window, anything dragged outside visible area triggers scroll bars) are met? Thanks in advance for any help.

Answer 1

The problem was that I did not have a DockPanel.Dock setting on the bottom child of the containing DockPanel. Relying on the DockPanel's LastChildFill wasn't enough to do the job. Once I set DockPanel.Dock = Bottom on the bottom child, the scroll bars started working.