如何使后退按关闭导航抽屉上的片段

Question

我已经为我的片段实现了一个导航抽屉，因此我想知道什么是实现片段的背压功能的最佳方法，以及代码必须要去的地方?我在下面使用了一些反向按压的代码，但它不起作用。

activity类

public class BakerlooHDNActivity extends AppCompatActivity {
    //save our header or result
    private Drawer result = null;
    private int getFactorColor(int color, float factor) {
        float[] hsv = new float[3];
        Color.colorToHSV(color, hsv);
        hsv[2] *= factor;
        color = Color.HSVToColor(hsv);
        return color;
    }
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_bakerloo_hdn);

        LocalBroadcastManager.getInstance(this).registerReceiver(onNotice, new IntentFilter("BACKPRESSED_TAG"));

        final String actionBarColor = "#B36305";
        Toolbar mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);
        if(getSupportActionBar()!=null) {
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(false);
            getSupportActionBar().setTitle(Html.fromHtml("<font color='#FFFFFF'>" + getResources().getString(R.string.hdn) + "</font>"));
            final Drawable upArrow = ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_mtrl_am_alpha);
            upArrow.setColorFilter(getResources().getColor(R.color.white), PorterDuff.Mode.SRC_ATOP);
            getSupportActionBar().setHomeAsUpIndicator(upArrow);
        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Window window = getWindow();
            window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
            getWindow().setStatusBarColor(getFactorColor(Color.parseColor(actionBarColor), 0.8f));
        }
        // start of navigation drawer
        AccountHeader headerResult = new AccountHeaderBuilder()
            .withActivity(this)
            .withCompactStyle(true)
            .withHeaderBackground(R.color.bakerloo)
            .withProfileImagesVisible(false)
            .withTextColor(Color.parseColor("#FFFFFF"))
            .withSelectionListEnabled(false)
            .addProfiles(
                    new ProfileDrawerItem().withName(getString(R.string.hello)).withEmail(getString(R.string.world))
            )
            .build();
        result = new DrawerBuilder()
            .withActivity(this)
            .withAccountHeader(headerResult)
            .withTranslucentStatusBar(false)
            .withActionBarDrawerToggle(false)
            .withSelectedItem(-1)
            .addDrawerItems(
                    new SectionDrawerItem().withName(R.string.other_lines_nocaps).setDivider(false),
                    new PrimaryDrawerItem().withName(R.string.hello_world).withIdentifier(1).withCheckable(false)
            )
            .build();
        // end of navigation drawer
    }

    @Override
    public void onBackPressed() {
        if (result.isDrawerOpen()) {
            result.closeDrawer();
        } else {
            super.onBackPressed();
        }
        LocalBroadcastManager.getInstance(context).sendBroadcast(new Intent("BACKPRESSED_TAG"));
    }
}

<<p> 片段类/strong>

public class FragmentBakerlooHDN extends android.support.v4.app.Fragment {
    public FragmentBakerlooHDN() {
        // Required empty constructor
    }
    BroadcastReceiver onNotice = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            // do stuff when back in activity is pressed
             headerResult.closeDrawer();
        }
    };
    // Declaring navigation drawer
    private AccountHeader headerResult = null;
    private Drawer result = null;

    /**
     * Whether or not the activity is in two-pane mode, i.e. running on a tablet
     * device.
     */
    private boolean mTwoPane;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        LocalBroadcastManager.getInstance(getActivity()).registerReceiver(onNotice, new IntentFilter("BACKPRESSED_TAG"));
        super.onCreate(savedInstanceState);
    }
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_bakerloo_hdn, container, false);

        headerResult = new AccountHeaderBuilder()
                .withActivity(getActivity())
                .withCompactStyle(true)
                .withHeaderBackground(R.color.bakerloo)
                .withProfileImagesVisible(false)
                .withTextColor(Color.parseColor("#FFFFFF"))
                .withSelectionListEnabled(false)
                .addProfiles(
                        new ProfileDrawerItem().withName(getString(R.string.hdn)).withEmail(getString(R.string.hello_world))
                )
                .build();
        result = new DrawerBuilder()
                .withActivity(getActivity())
                .withAccountHeader(headerResult)
                .withTranslucentStatusBar(false)
                .withActionBarDrawerToggle(false)
                .withSelectedItem(-1)
                .addDrawerItems(
                new PrimaryDrawerItem().withName(R.string.hello_world).withIdentifier(1).withCheckable(false)
                )
                .build();

        super.onCreate(savedInstanceState);
        return v;
    }
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        View v = getView();
        super.onActivityCreated(savedInstanceState);
    }
}

Answer 1

Fragment中没有onBackPressed()。这是Activity的方法。你能做的，你可以让你的活动调用你的fragment方法时，它的onBackPressed()被调用:

@Override
public void onBackPressed() {
    if (!frag.onBackPressed() ) {
        super.onBackPressed();
    }
}

，然后你的片段的onBackPressed() could do anything you want and return true when it done anything, or false '，否则，所以你可以调用super的一个在这种情况下