我如何在 PreferenceFragment 的操作栏中设置后退按钮 ..？

Question

----------------------------------- ------------Xml-代码------------------------------------ ------------------------------------

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory android:title="Notification Settings">
    <SwitchPreference
        android:defaultValue="true"
        android:key="notification_state"
        android:summary="Notification is Enabled"
        android:title="Show Notification" />
    <Preference
        android:key="reset_data"
        android:summary="All data will be removed"
        android:title="Reset Data" />
</PreferenceCategory>
</PreferenceScreen>

----------------------------------- ----------Java代码-------------------------- ----------------------

import android.content.DialogInterface;
import android.content.DialogInterface.OnClickListener;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.Bundle;
import android.preference.Preference;
import android.preference.Preference.OnPreferenceChangeListener;
import android.preference.Preference.OnPreferenceClickListener;
import android.preference.PreferenceManager;
import android.support.v4.app.NavUtils;
import android.support.v7.app.AlertDialog;
import android.view.MenuItem;
import android.widget.Toast;

import com.internet.services.DataService;
import com.github.machinarius.preferencefragment.PreferenceFragment;


public class SettingsActivity extends PreferenceFragment {
    SharedPreferences dataPref;

    public void onStart() {
        super.onStart();
        dataPref = PreferenceManager.getDefaultSharedPreferences(getActivity());
    }


    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);

        findPreference("notification_state").setOnPreferenceChangeListener(new OnPreferenceChangeListener() {
            @Override
            public boolean onPreferenceChange(Preference preference, Object newValue) {
                boolean isNotificationOn = (Boolean) newValue;
                Editor edit = dataPref.edit();
                edit.putBoolean("notification_state", isNotificationOn);
                edit.apply();
                if (isNotificationOn) {
                    findPreference("notification_state").setSummary("Notification is Enabled");
                } else {
                    findPreference("notification_state").setSummary("Notification is Disabled");
                }
                return true;
            }
        });
        findPreference("reset_data").setOnPreferenceClickListener(new OnPreferenceClickListener() {
            @Override
            public boolean onPreferenceClick(Preference preference) {
                AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
                builder.setMessage("All Data Will Be Clear!").setCancelable(false).setPositiveButton("Yes", new OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        SharedPreferences sp_today = getActivity().getSharedPreferences(DataService.TODAY_DATA, 0);
                        SharedPreferences sp_month = getActivity().getSharedPreferences(DataService.MONTH_DATA, 0);
                        Editor editor = sp_today.edit();
                        Editor edito2 = sp_month.edit();
                        editor.clear();
                        edito2.clear();
                        editor.apply();
                        edito2.apply();
                        Toast.makeText(getActivity(), "Data Removed", Toast.LENGTH_LONG).show();
                    }
                }).setNegativeButton("No", new OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });
                AlertDialog alert = builder.create();
                alert.setTitle("Do You Want To Reset Data?");
                alert.show();
                return true;
            }
        });
    }

    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case 16908332:
                NavUtils.navigateUpFromSameTask(getActivity());
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }


}

Answer 1

您已通过以下代码设置启用返回按钮

 ActionBar actionBar = getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);

在 onCreate() 方法中以及单击该按钮后的代码会发生什么

 @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == android.R.id.home) {
            finish();
        } 
        return super.onOptionsItemSelected(item);
    }