class MainActivity : ComponentActivity() {
    @SuppressLint("CoroutineCreationDuringComposition", "UnrememberedMutableState")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent { // ← システム提供のCompositionLocalの状態を保持
            androidx.compose.ui.platform.LocalContext
            MyApplicationTheme {
                // アプリのコンテンツ
            }
        }
    }
}

@Composable
@OptIn(ExperimentalComposeUiApi::class)
internal fun ProvideAndroidCompositionLocals(
    owner: AndroidComposeView,
    content: @Composable () -> Unit
) {
    val view = owner
    val context = view.context
    var configuration by remember {
        mutableStateOf(
            context.resources.configuration,
            neverEqualPolicy()
        )
    }

    ...

    val imageVectorCache = obtainImageVectorCache(context, configuration)
    CompositionLocalProvider(
        LocalConfiguration provides configuration,
        LocalContext provides context,
        LocalLifecycleOwner provides viewTreeOwners.lifecycleOwner,
        LocalSavedStateRegistryOwner provides viewTreeOwners.savedStateRegistryOwner,
        LocalSaveableStateRegistry provides saveableStateRegistry,
        LocalView provides owner.view,
        LocalImageVectorCache provides imageVectorCache
    ) {
        ProvideCommonCompositionLocals(
            owner = owner,
            uriHandler = uriHandler,
            content = content
        )
    }
}

@OptIn(ExperimentalTextApi::class)
@ExperimentalComposeUiApi
@Composable
internal fun ProvideCommonCompositionLocals(
    owner: Owner,
    uriHandler: UriHandler,
    content: @Composable () -> Unit
) {
    CompositionLocalProvider(
        LocalAccessibilityManager provides owner.accessibilityManager,
        LocalAutofill provides owner.autofill,
        LocalAutofillTree provides owner.autofillTree,
        LocalClipboardManager provides owner.clipboardManager,
        LocalDensity provides owner.density,
        LocalFocusManager provides owner.focusOwner,
        @Suppress("DEPRECATION") LocalFontLoader
            providesDefault @Suppress("DEPRECATION") owner.fontLoader,
        LocalFontFamilyResolver providesDefault owner.fontFamilyResolver,
        LocalHapticFeedback provides owner.hapticFeedBack,
        LocalInputModeManager provides owner.inputModeManager,
        LocalLayoutDirection provides owner.layoutDirection,
        LocalTextInputService provides owner.textInputService,
        LocalPlatformTextInputPluginRegistry provides owner.platformTextInputPluginRegistry,
        LocalTextToolbar provides owner.textToolbar,
        LocalUriHandler provides uriHandler,
        LocalViewConfiguration provides owner.viewConfiguration,
        LocalWindowInfo provides owner.windowInfo,
        LocalPointerIconService provides owner.pointerIconService,
        content = content
    )
}

    :
	:
/**
 * The Android [Configuration]. The [Configuration] is useful for determining how to organize the
 * UI.
 */
val LocalConfiguration = compositionLocalOf<Configuration>(
    neverEqualPolicy()
) {
    noLocalProvidedFor("LocalConfiguration")
}

/**
 * Provides a [Context] that can be used by Android applications.
 */
val LocalContext = staticCompositionLocalOf<Context> {
    noLocalProvidedFor("LocalContext")
}
    :
	:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">LocalContext Sample</string>
    <string name="greeting">こんにちは アンドロイド!</string>
</resources>

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyApplicationTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    Greeting()
                }
            }
        }
    }
}

@Composable
fun Greeting(modifier: Modifier = Modifier) {
    val _text = LocalContext.current.resources.getString(R.string.greeting)
    Text(
        text = _text,
        modifier = modifier
    )
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">

    <application ...>
        <activity
            android:name=".MainActivity"
            android:configChanges="orientation"
            android:exported="true"
            android:label="@string/app_name"
            android:theme="@style/Theme.MyApplication">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MyApplicationTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    ElementA()
                }
            }
        }
    }
}

@Composable
fun ElementA() {
    ElementB()
}
@Composable
fun ElementB() {
    ElementC()
}
@Composable
fun ElementC() {
    val _text = when(LocalConfiguration.current.orientation) {
        Configuration.ORIENTATION_LANDSCAPE -> "Landscape !"
        Configuration.ORIENTATION_PORTRAIT -> "Portrait !"
        else -> "Unknown !"
    }
    Text(text = _text)
}