问题

我在 `MaterialApp` 上使用了 `textDirection: TextDirection.rtl`：

```dart
return const MaterialApp(
      debugShowCheckedModeBanner: false,
      title: appTitle,
      home: Directionality(
        textDirection: TextDirection.rtl,
        child: MyHomePage(title: appTitle),
      ),
    );

所有内容都右对齐，工作得很好，除了 AppBar 的返回按钮。

当你导航到其他页面（具体来说，我在使用 drawer）时，返回按钮会被左对齐而不是右对齐。

导航代码：

Navigator.push(
  context,
  MaterialPageRoute(
    builder: (BuildContext context) => const SettingsView(),
  ),
);

"Settings" 页面：

return Scaffold(
      appBar: AppBar(title: Text("Settings"))
    );

如你所见，我没有触及 leading 属性，我以为它应该是自动的...

<details>
<summary>英文:</summary>

I am using `textDirection: TextDirection.rtl` on the `MaterialApp`:

return const MaterialApp(
debugShowCheckedModeBanner: false,
title: appTitle,
home: Directionality(
textDirection: TextDirection.rtl,
child: MyHomePage(title: appTitle),
),
);

Everything is aligned to right and works perfectly, except for the back button of the `AppBar`. 

When you navigate to other pages (specifically I'm using `drawer`) the back button is aligned to the left and not to the right.

[![appbar back button left aligned][1]][1]

Navigation code:

Navigator.push(
context,
MaterialPageRoute(
builder: (BuildContext context) => const SettingsView(),
),
);

"Settings" page:

return Scaffold(
appBar: AppBar(title: Text("Settings"))
);

As you can see I didn't touch the `leading` property, I thought it should be automatically...

  [1]: https://i.stack.imgur.com/JVJTX.png

</details>


# 答案1
**得分**: 1

```dart
我正在使用`builder`来处理这个。

```dart
void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: HomeScreen(),
      builder: (context, child) => Directionality(
        textDirection: TextDirection.rtl,
        child: child ?? const SizedBox.shrink(),
      ),
    );
  }
}

class SettingPage extends StatelessWidget {
  const SettingPage({super.key});

  @override
  Widget build(BuildContext context) {
    print(Directionality.of(context).toString());
    return Scaffold(
      appBar: AppBar(
        title: Text("Settings"),
      ),
    );
  }
}

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: HomeScreen(),
      builder: (context, child) => Directionality(
        textDirection: TextDirection.rtl,
        child: child ?? const SizedBox.shrink(),
      ),
    );
  }
}

class SettingPage extends StatelessWidget {
  const SettingPage({super.key});

  @override
  Widget build(BuildContext context) {
    print(Directionality.of(context).toString());
    return Scaffold(
      appBar: AppBar(
        title: Text("Settings"),
      ),
    );
  }
}