Sheets, Scrim, and Dialogs

These controls use xmlns:m3c="using:Material3.Avalonia.Controls".

In-place overlays

BottomSheet, SideSheet, Scrim, and DialogPane are not popups and do not move themselves to a top-level overlay. Place them after page content in a shared Panel; that panel's bounds define the covered region.

BottomSheet

<Panel>
    <Grid>
        <Button Content="Open sheet" Command="{Binding OpenSheetCommand}" />
    </Grid>

    <m3c:BottomSheet IsOpen="{Binding IsSheetOpen}"
                     Closed="OnSheetClosed">
        <StackPanel Margin="24,8,24,24" Spacing="8">
            <TextBlock Classes="title-medium" Text="Bottom sheet" />
            <TextBlock Text="Tap the scrim or drag down to dismiss." />
        </StackPanel>
    </m3c:BottomSheet>
</Panel>

Member	Type	Default	Description
IsOpen	bool	false	Two-way by default.
ShowDragHandle	bool	true	Shows the handle and its drag interaction area.
Closed	event EventHandler	-	Raised when IsOpen changes to false.

Dragging starts from the handle. Releasing after the dismiss threshold closes the sheet; otherwise it returns to the open position. Pressing the built-in scrim also closes it.

SideSheet

<Panel>
    <ContentControl Content="{Binding CurrentPage}" />

    <m3c:SideSheet IsOpen="{Binding IsDetailsOpen}">
        <StackPanel Margin="24" Spacing="12">
            <TextBlock Classes="title-large" Text="Details" />
            <TextBlock Text="Supporting information" />
        </StackPanel>
    </m3c:SideSheet>
</Panel>

SideSheet exposes IsOpen and Closed. It supports scrim and Escape-key dismissal but does not expose a drag handle or drag gesture.

Scrim

Use standalone Scrim when composing your own overlay. It raises Dismissed but does not close itself.

<m3c:Scrim IsOpen="{Binding IsDialogOpen}"
            Dismissed="OnScrimDismissed" />

private void OnScrimDismissed(object? sender, EventArgs e)
{
    IsDialogOpen = false;
}

DialogPane

DialogPane is the visual dialog surface. It does not create a Window or Popup, trap focus, provide modality, or return a result.

<Panel>
    <ContentControl Content="{Binding CurrentPage}" />
    <m3c:Scrim IsOpen="{Binding IsDialogOpen}" />

    <m3c:DialogPane Title="Delete item?"
                    IsVisible="{Binding IsDialogOpen}"
                    HorizontalAlignment="Center"
                    VerticalAlignment="Center">
        <TextBlock Text="This operation cannot be undone." />

        <m3c:DialogPane.Buttons>
            <StackPanel Orientation="Horizontal" Spacing="8">
                <Button Classes="text" Content="Cancel"
                        Command="{Binding CancelCommand}" />
                <Button Classes="text danger" Content="Delete"
                        Command="{Binding DeleteCommand}" />
            </StackPanel>
        </m3c:DialogPane.Buttons>
    </m3c:DialogPane>
</Panel>

Property	Type	Default	Description
Title	string?	null	Optional headline.
Icon	object?	null	Optional centered hero icon.
Buttons	object?	null	Action slot; wrap multiple buttons in a panel.
Content	inherited	null	Dialog body.

Applications remain responsible for focus management, Escape handling, results, and modal behavior.