package gq.cyuubi.lightswitch; import android.os.Bundle; import androidx.appcompat.app.ActionBar; import androidx.appcompat.app.AppCompatActivity; import androidx.appcompat.widget.Toolbar; import androidx.preference.PreferenceFragmentCompat; public class SettingsActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.settings_activity); getSupportFragmentManager() .beginTransaction() .replace(R.id.settings, new HeaderFragment()) .commit(); setSupportActionBar((Toolbar) findViewById(R.id.toolbar)); ActionBar actionBar = getSupportActionBar(); if (actionBar != null) { actionBar.setDisplayHomeAsUpEnabled(true); } } public static class HeaderFragment extends PreferenceFragmentCompat { @Override public void onCreatePreferences(Bundle savedInstanceState, String rootKey) { setPreferencesFromResource(R.xml.preferences, rootKey); } } }