Flutter 中的动态启动画面

Question

我有不同版本的本机启动画面，我想在之前在应用中选择其主题时显示每个版本。例如，假设我有一个浅色闪屏和一个深色闪屏，并且默认情况下会显示浅色，但是如果用户在应用设置中将应用主题更改为深色主题，那么除了我要进行的更改在我的应用程序中执行此操作，下次用户打开应用程序时，我想向他显示初始屏幕的深色版本。

注意：我说的是原生启动画面

Answer 1

我想说共享偏好可以是实现这一目标的方法之一。
经过一番努力，我想出了下面的示例代码：
ma​​in.dart

SharedPreferences prefs;
String theme;

void main() async {
  prefs = await SharedPreferences.getInstance();
  // just for checking purpose
  if (prefs.getString("theme") == null) {
    await prefs.setString("theme", "darkTheme");
  }
  theme = (prefs.getString("theme") != null) ? "darkTheme" : "lightTheme";
  WidgetsFlutterBinding.ensureInitialized();
  runApp(MyApp(theme: theme));
}

class MyApp extends StatelessWidget {
  final theme;

  const MyApp({Key key, this.theme}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    Brightness themeData =
        theme == "darkTheme" ? Brightness.dark : Brightness.light;
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(brightness: themeData),
      home: theme == "darkTheme"
          ? Scaffold(
              body: Center(
                child: Container(
                  child: Text("Dark Theme"),
                ),
              ),
            )
          : Scaffold(
              body: Center(
                child: Container(
                  child: Text("Light Theme"),
                ),
              ),
            ),
      debugShowCheckedModeBanner: false,
    );
  }
}

MainActivity.kt

import android.content.Context
import android.content.SharedPreferences
import io.flutter.embedding.android.FlutterActivity

class MainActivity : FlutterActivity() {
    var sharedPreferences: SharedPreferences =
            getSharedPreferences("FlutterSharedPreferences", 0)
    private val theme: String? = sharedPreferences.getString("flutter." + "theme", "lightTheme")
    override fun setTheme(resid: Int) {
        super.setTheme(resid)
        if (theme == "darkTheme") {
            application.setTheme(R.style.LaunchTheme)
        }
        if (theme == "lightTheme") {
            application.setTheme(R.style.NormalTheme)
        }
    }
}

styles.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
        <item name="android:windowEnableSplitTouch">false</item>
        <item name="android:splitMotionEvents">false</item>
        <item name="android:windowBackground">@android:color/black</item>
    </style>

    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
        <item name="android:windowBackground">@android:color/white</item>
        <item name="android:windowEnableSplitTouch">false</item>
        <item name="android:splitMotionEvents">false</item>
    </style>
</resources>

仅供参考：-

最终，Flutter 将值存储在原生共享偏好中。数据的检索格式不同。

Android：

var sharedPreferences: SharedPreferences =
            getSharedPreferences("FlutterSharedPreferences", 0)
    private val theme: String? = sharedPreferences.getString("flutter." + "theme", "lightTheme")

IOS：

if let name = NSUserDefaults.standard.string(forKey: "flutter.test") {
    print(name)
}

参考：-

ios, android

此代码对我有用。 :)