我有一个支持多语言的旧项目。我要升级支持库和目标平台，在迁移到 Androidx 之前一切正常，但现在更改语言不起作用!

我使用此代码更改 App 的默认语言环境

private static Context updateResources(Context context, String language)
{
    Locale locale = new Locale(language);
    Locale.setDefault(locale);

    Configuration configuration = context.getResources().getConfiguration();
    configuration.setLocale(locale);

    return context.createConfigurationContext(configuration);
}

@Override
protected void attachBaseContext(Context newBase)
{
    SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
    String language = preferences.getString(SELECTED_LANGUAGE, "fa");
    super.attachBaseContext(updateResources(newBase, language));
}

<TextView
    android:id="@+id/textView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/app_name"/>

最佳答案

2020 年 8 月 21 日更新:
AppCompat 1.2.0 终于发布了。如果您不使用 ContextWrapper或 ContextThemeWrapper根本没有其他事情可做，您应该能够从 1.1.0 中删除任何解决方法!
如果您确实使用 ContextWrapper或 ContextThemeWrapper里面 attachBaseContext , 语言环境更改将中断，因为当您将包装的上下文传递给 super 时，

package androidx.appcompat.app

import android.content.Context
import android.content.res.Configuration
import android.os.Bundle
import android.util.AttributeSet
import android.view.MenuInflater
import android.view.View
import android.view.ViewGroup
import androidx.appcompat.view.ActionMode
import androidx.appcompat.widget.Toolbar

class BaseContextWrappingDelegate(private val superDelegate: AppCompatDelegate) : AppCompatDelegate() {

    override fun getSupportActionBar() = superDelegate.supportActionBar

    override fun setSupportActionBar(toolbar: Toolbar?) = superDelegate.setSupportActionBar(toolbar)

    override fun getMenuInflater(): MenuInflater? = superDelegate.menuInflater

    override fun onCreate(savedInstanceState: Bundle?) {
        superDelegate.onCreate(savedInstanceState)
        removeActivityDelegate(superDelegate)
        addActiveDelegate(this)
    }

    override fun onPostCreate(savedInstanceState: Bundle?) = superDelegate.onPostCreate(savedInstanceState)

    override fun onConfigurationChanged(newConfig: Configuration?) = superDelegate.onConfigurationChanged(newConfig)

    override fun onStart() = superDelegate.onStart()

    override fun onStop() = superDelegate.onStop()

    override fun onPostResume() = superDelegate.onPostResume()

    override fun setTheme(themeResId: Int) = superDelegate.setTheme(themeResId)

    override fun <T : View?> findViewById(id: Int) = superDelegate.findViewById<T>(id)

    override fun setContentView(v: View?) = superDelegate.setContentView(v)

    override fun setContentView(resId: Int) = superDelegate.setContentView(resId)

    override fun setContentView(v: View?, lp: ViewGroup.LayoutParams?) = superDelegate.setContentView(v, lp)

    override fun addContentView(v: View?, lp: ViewGroup.LayoutParams?) = superDelegate.addContentView(v, lp)

    override fun attachBaseContext2(context: Context) = wrap(superDelegate.attachBaseContext2(super.attachBaseContext2(context)))

    override fun setTitle(title: CharSequence?) = superDelegate.setTitle(title)

    override fun invalidateOptionsMenu() = superDelegate.invalidateOptionsMenu()

    override fun onDestroy() {
        superDelegate.onDestroy()
        removeActivityDelegate(this)
    }

    override fun getDrawerToggleDelegate() = superDelegate.drawerToggleDelegate

    override fun requestWindowFeature(featureId: Int) = superDelegate.requestWindowFeature(featureId)

    override fun hasWindowFeature(featureId: Int) = superDelegate.hasWindowFeature(featureId)

    override fun startSupportActionMode(callback: ActionMode.Callback) = superDelegate.startSupportActionMode(callback)

    override fun installViewFactory() = superDelegate.installViewFactory()

    override fun createView(parent: View?, name: String?, context: Context, attrs: AttributeSet): View? = superDelegate.createView(parent, name, context, attrs)

    override fun setHandleNativeActionModesEnabled(enabled: Boolean) {
        superDelegate.isHandleNativeActionModesEnabled = enabled
    }

    override fun isHandleNativeActionModesEnabled() = superDelegate.isHandleNativeActionModesEnabled

    override fun onSaveInstanceState(outState: Bundle?) = superDelegate.onSaveInstanceState(outState)

    override fun applyDayNight() = superDelegate.applyDayNight()

    override fun setLocalNightMode(mode: Int) {
        superDelegate.localNightMode = mode
    }

    override fun getLocalNightMode() = superDelegate.localNightMode

    private fun wrap(context: Context): Context {
        TODO("your wrapping implementation here")
    }
}

private var baseContextWrappingDelegate: AppCompatDelegate? = null

override fun getDelegate() = baseContextWrappingDelegate ?: BaseContextWrappingDelegate(super.getDelegate()).apply {
    baseContextWrappingDelegate = this
}

override fun createConfigurationContext(overrideConfiguration: Configuration) : Context {
    val context = super.createConfigurationContext(overrideConfiguration)
    TODO("your wrapping implementation here")
}

 final Configuration conf = new Configuration();
 conf.uiMode = newNightMode | (conf.uiMode & ~Configuration.UI_MODE_NIGHT_MASK);

 try {
     ...
     ((android.view.ContextThemeWrapper) mHost).applyOverrideConfiguration(conf);
     handled = true;
 } catch (IllegalStateException e) {
     ...
 }

final Configuration conf = new Configuration(baseConfiguration);
conf.uiMode = newNightMode | (conf.uiMode & ~Configuration.UI_MODE_NIGHT_MASK);
try {
    ...
    ((android.view.ContextThemeWrapper) mHost).applyOverrideConfiguration(conf);
    handled = true;
} catch (IllegalStateException e) {
    ...
}

override fun applyOverrideConfiguration(overrideConfiguration: Configuration?) {
    if (overrideConfiguration != null) {
        val uiMode = overrideConfiguration.uiMode
        overrideConfiguration.setTo(baseContext.resources.configuration)
        overrideConfiguration.uiMode = uiMode
    }
    super.applyOverrideConfiguration(overrideConfiguration)
}

@Override
public void applyOverrideConfiguration(Configuration overrideConfiguration) {
    if (overrideConfiguration != null) {
        int uiMode = overrideConfiguration.uiMode;
        overrideConfiguration.setTo(getBaseContext().getResources().getConfiguration());
        overrideConfiguration.uiMode = uiMode;
    }
    super.applyOverrideConfiguration(overrideConfiguration);
}

private var activityHandlesUiMode = false
private var activityHandlesUiModeChecked = false

private val isActivityManifestHandlingUiMode: Boolean
    get() {
        if (!activityHandlesUiModeChecked) {
            val pm = packageManager ?: return false
            activityHandlesUiMode = try {
                val info = pm.getActivityInfo(ComponentName(this, javaClass), 0)
                info.configChanges and ActivityInfo.CONFIG_UI_MODE != 0
            } catch (e: PackageManager.NameNotFoundException) {
                false
            }
        }
        activityHandlesUiModeChecked = true
        return activityHandlesUiMode
    }

override fun onConfigurationChanged(newConfig: Configuration) {
    if (isActivityManifestHandlingUiMode) {
        val nightMode = if (delegate.localNightMode != AppCompatDelegate.MODE_NIGHT_UNSPECIFIED) 
            delegate.localNightMode
        else
            AppCompatDelegate.getDefaultNightMode()
        val configNightMode = when (nightMode) {
            AppCompatDelegate.MODE_NIGHT_YES -> Configuration.UI_MODE_NIGHT_YES
            AppCompatDelegate.MODE_NIGHT_NO -> Configuration.UI_MODE_NIGHT_NO
            else -> applicationContext.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK
        }
        newConfig.uiMode = configNightMode or (newConfig.uiMode and Configuration.UI_MODE_NIGHT_MASK.inv())
    }
    super.onConfigurationChanged(newConfig)
}

关于android - 迁移到 Androidx 后更改区域设置不起作用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/55265834/