maui-safe-area（毛伊岛安全区）

Safe Area — Gotchas & Best Practices (.NET 10+)

Breaking Changes

⚠️.NET 9 → 10: ContentPage default changed to None

ContentPage now defaults to edge-to-edge (None) on all platforms. In.NET 9, Android ContentPage behaved like Container. If your Android content goes under the status bar after upgrading, add SafeAreaEdges="Container" explicitly.

<!-- ❌ .NET 10 default — content goes under status bar on Android -->
<ContentPage>

<!-- ✅ Restore .NET 9 Android behavior -->
<ContentPage SafeAreaEdges="Container">

⚠️ WindowSoftInputModeAdjust.Resize migration

If you used WindowSoftInputModeAdjust.Resize in.NET 9, you may need SafeAreaEdges="All" on the ContentPage to maintain keyboard avoidance.

Common Gotchas

1. Layouts default to Container, not None

For true edge-to-edge, set SafeAreaEdges="None" on both the page and layouts:

<!-- ❌ Grid still respects system bars (its default is Container) -->
<ContentPage SafeAreaEdges="None">
    <Grid>
        <Image Source="bg.jpg" Aspect="AspectFill" />
    </Grid>
</ContentPage>

<!-- ✅ Both page and layout set to None -->
<ContentPage SafeAreaEdges="None">
    <Grid SafeAreaEdges="None">
        <Image Source="bg.jpg" Aspect="AspectFill" />
    </Grid>
</ContentPage>

2. SoftInput on ScrollView has no effect

ScrollView manages its own content insets. Wrap it in a Grid/StackLayout instead:

<!-- ❌ SoftInput is ignored on ScrollView -->
<ScrollView SafeAreaEdges="SoftInput">

<!-- ✅ Set SoftInput on the wrapper layout -->
<Grid SafeAreaEdges="Container, Container, Container, SoftInput">
    <ScrollView> ... </ScrollView>
</Grid>

3. Default is not None

Default = "use platform defaults for this control type." None = "edge-to-edge." They differ significantly on ScrollView (iOS maps Default to automatic content insets).

4. Blazor Hybrid double-padding

<!-- ❌ XAML safe area + CSS env() = double padding -->
<ContentPage SafeAreaEdges="Container">
    <BlazorWebView ... />  <!-- CSS also uses env(safe-area-inset-*) -->

<!-- ✅ Pick ONE approach — CSS is recommended for Blazor -->
<ContentPage SafeAreaEdges="None">
    <BlazorWebView ... />  <!-- CSS handles all insets with env() -->

5. iOS Shell/NavigationPage edge-to-edge

Content won't extend behind the nav bar unless you set a transparent background AND hide the separator:

<Shell Shell.BackgroundColor="#80000000"
       Shell.NavBarHasShadow="False" />

Decision Framework

Migration Quick Reference

Legacy properties still work but are obsolete.

Best Practices

1. Combine SafeAreaEdges with Padding — safe area handles insets, Padding adds visual spacing: <ContentPage SafeAreaEdges="All"> <VerticalStackLayout Padding="20"> <!-- Both applied — no conflict --> </VerticalStackLayout> </ContentPage>
2. Use per-control settings for mixed layouts (edge-to-edge header + safe body + keyboard-aware footer).
3. For Blazor Hybrid, prefer CSS env() and leave SafeAreaEdges="None". Add viewport-fit=cover to the <meta viewport> tag.
4. Test on notched devices (iPhone X+, Android cutouts), tablets in landscape, and varying screen sizes.

Checklist

• Android upgrade: SafeAreaEdges="Container" added if content goes under status bar
• Edge-to-edge: None set on both page and layout
• ScrollView keyboard avoidance uses wrapper Grid, not ScrollView's own SafeAreaEdges
• Blazor Hybrid: using either XAML or CSS safe areas, not both
• viewport-fit=cover in Blazor's index.html <meta viewport> tag
• Legacy UseSafeArea / IgnoreSafeArea migrated to SafeAreaEdges