【发布时间】:2020-10-03 22:09:45
【问题描述】:
我尝试实现可直接从设置中更改的日/夜系统。我为此使用了 PreferenceFragmentCompat,但是,当我按下切换首选项以更改模式时。我有以下错误:
E/Parcel: Class not found when unmarshalling: androidx.fragment.app.FragmentManagerState
java.lang.ClassNotFoundException: androidx.fragment.app.FragmentManagerState
Caused by: java.lang.ClassNotFoundException: androidx.fragment.app.FragmentManagerState
Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available
我到处找,但我真的不明白错误来自哪里..
这是我的偏好活动:
public class PreferencesActivity extends AppCompatActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_preferences);
PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(this);
if (savedInstanceState == null)
getSupportFragmentManager().beginTransaction().replace(R.id.preferences_container, new PreferencesFragment()).commit();
}
@Override
protected void onDestroy() {
super.onDestroy();
PreferenceManager.getDefaultSharedPreferences(this).unregisterOnSharedPreferenceChangeListener(this);
}
@Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
if(key.contains(getString(R.string.KEY_PREF_NIGHT_MODE)))
AppCompatDelegate.setDefaultNightMode(sharedPreferences.getBoolean(key, false)? AppCompatDelegate.MODE_NIGHT_YES: AppCompatDelegate.MODE_NIGHT_NO);
}
public static class PreferencesFragment extends PreferenceFragmentCompat {
@Override
public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
setPreferencesFromResource(R.xml.preferences, rootKey);
}
}
}
我使用这个布局:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/noteRecyclerBackground"
tools:context=".PreferencesActivity">
<FrameLayout
android:id="@+id/preferences_container"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</FrameLayout>
</LinearLayout>
【问题讨论】:
-
它在哪一行崩溃了,你检查你的导入了吗?确保您没有将
androidx类与框架或支持 lib 类混合。 -
没有崩溃,但出现错误,这是使用
AppCompatDelegate.setDefaultNightMode(sharedPreferences.getBoolean(key, false)? AppCompatDelegate.MODE_NIGHT_YES: AppCompatDelegate.MODE_NIGHT_NO);重新启动活动时
标签: java android android-activity fragment preferences