导航抽屉从右到左？

Question

我正在使用android studio 3.1，我想更换抽屉，以便从右侧显示。我尝试了android:layout_gravity="end"，当从rtl转换时，这对我很有用，但当我点击它时，我仍然有一个问题，左侧的菜单按钮停止了

我想我必须将其更改为右侧，但我不知道如何

MainActivity.java：

public class MainActivity extends AppCompatActivity {
private final String TAG = MainActivity.class.getSimpleName();
private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;

//Defining Variables
private Toolbar toolbar;
private NavigationView navigationView;
private DrawerLayout drawerLayout;
private int previousDrawerItemChecked;
private SearchView searchView;

private BroadcastReceiver mRegistrationBroadcastReceiver;
//private ProgressBar mRegistrationProgressBar;
//private TextView mInformationTextView;
private boolean isReceiverRegistered;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Initializing Toolbar and setting it as the actionbar
    toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    //Initializing NavigationView
    navigationView = (NavigationView) findViewById(R.id.navigation_view);

    //Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

        // This method will trigger on item Click of navigation menu
        @Override
        public boolean onNavigationItemSelected(MenuItem menuItem) {


            //Checking if the item is in checked state or not, if not make it in checked state
            if(menuItem.isChecked()) menuItem.setChecked(false);
            else menuItem.setChecked(true);

            //Closing drawer on item click
            drawerLayout.closeDrawers();

            //Check to see which item was being clicked and perform appropriate action
            switch (menuItem.getItemId()){
                //Replacing the main content with ContentFragment Which is our Inbox View;
                case R.id.recently_added:
                    sub_recently_added();
                    previousDrawerItemChecked = 0;
                    return true;
                case R.id.categories:
                    sub_labels_results();
                    previousDrawerItemChecked = 1;
                    return true;
                case R.id.popular:
                    sub_label_results(Const.BLOGGER_FEATURED_CATEGORY);
                    previousDrawerItemChecked = 2;
                    return true;
                case R.id.about:
                    sub_about_fragment();
                    previousDrawerItemChecked = 3;
                    return true;
                case R.id.rate_app:
                    Uri uri = Uri.parse("market://details?id=" + getApplicationContext().getPackageName());
                    Intent goToMarket = new Intent(Intent.ACTION_VIEW, uri);
                    // To count with Play market backstack, After pressing back button,
                    // to taken back to our application, we need to add following flags to intent.
                    goToMarket.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY |
                            Intent.FLAG_ACTIVITY_NEW_DOCUMENT |
                            Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
                    try {
                        startActivity(goToMarket);
                    } catch (ActivityNotFoundException e) {
                        startActivity(new Intent(Intent.ACTION_VIEW,
                                Uri.parse("http://play.google.com/store/apps/details?id=" + getApplicationContext().getPackageName())));
                    }
                    return true;
                default:
                    Toast.makeText(getApplicationContext(),"Somethings Wrong",Toast.LENGTH_SHORT).show();
                    return true;

            }
        }
    });

    // Initializing Drawer Layout and ActionBarToggle
    drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
    ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.openDrawer, R.string.closeDrawer){

        @Override
        public void onDrawerClosed(View drawerView) {
            // Code here will be triggered once the drawer closes as we dont want anything to happen so we leave this blank
            super.onDrawerClosed(drawerView);
        }

        @Override
        public void onDrawerOpened(View drawerView) {
            // Code here will be triggered once the drawer open as we dont want anything to happen so we leave this blank

            super.onDrawerOpened(drawerView);
        }
    };

    //Setting the actionbarToggle to drawer layout
    drawerLayout.setDrawerListener(actionBarDrawerToggle);

    //calling sync state is necessay or else your hamburger icon wont show up
    actionBarDrawerToggle.syncState();


    if (savedInstanceState == null) {
        sub_recently_added();
        previousDrawerItemChecked = 0;
    }

    if (AppController.getInstance().getPrefManger().getFirstLaunched()){
        //Sending Broadcast to LabelsController
        Intent intent = new Intent();
        intent.setAction(Const.PACKAGE_INTENT);
        sendBroadcast(intent);
        AppController.getInstance().getPrefManger().setFirstLaunched(false);
    }

}

@Override
public boolean onCreateOptionsMenu(final Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);

    // Associate searchable configuration with the SearchView
    SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
    searchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
    searchView.setQueryHint(getString(R.string.search_hint));
    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {

        @Override
        public boolean onQueryTextChange(String newText) {
            return false;
        }

        @Override
        public boolean onQueryTextSubmit(String query) {
            toolbar.setSubtitle("Search Results for: " + query);
            searchView.onActionViewCollapsed();
            searchView.setQuery("", false);
            searchView.clearFocus();
            //menu.findItem(R.id.action_search).collapseActionView();

            sub_search_results(query);
            return true;
        }
    });
    searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));

    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    return super.onOptionsItemSelected(item);
}

@Override
public void onBackPressed(){

    FragmentManager fm = getSupportFragmentManager();
    if (fm.getBackStackEntryCount()>0){

        String title = fm.getBackStackEntryAt(fm.getBackStackEntryCount()-1).getName();
        fm.addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
            @Override
            public void onBackStackChanged() {
                FragmentManager manager = getSupportFragmentManager();
                if (manager != null) {
                    int backStackEntryCount = manager.getBackStackEntryCount();
                    if (backStackEntryCount == 0) {
                        finish();
                    }
                    if ((backStackEntryCount - 1)>=0) {
                        Fragment fragment = manager.getFragments().get(backStackEntryCount - 1);
                        fragment.onResume();
                    }
                }

            }
        });
        fm.getBackStackEntryAt(fm.getBackStackEntryCount() - 1);
        int pos = Integer.parseInt(title);
        navigationView.getMenu().getItem(pos).setChecked(true);
        fm.popBackStack();

    }else{
        getSupportActionBar().setSubtitle(null);
        super.onBackPressed();
    }

}

private void sub_recently_added(){
    toolbar.setSubtitle(R.string.menu_recently_added);
    Fragment fragment = RecentFragment.newInstance(0, getString(R.string.menu_recently_added));
    android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.frame, fragment);
    fragmentTransaction.addToBackStack("" + previousDrawerItemChecked).commit();
}

private void sub_search_results(String searchQuery){
    Fragment fragment = SearchFragment.newInstance(searchQuery);
    android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.frame, fragment);
    fragmentTransaction.addToBackStack("" + previousDrawerItemChecked).commit();
}

public void sub_label_results(String label){
    toolbar.setSubtitle("Category: " + label);
    Fragment fragment = LabelsFragment.newInstance(label);
    android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.frame, fragment);
    fragmentTransaction.addToBackStack("" + previousDrawerItemChecked).commit();
}

private void sub_labels_results(){
    toolbar.setSubtitle("Categories");
    Fragment fragment = LabelsListFragment.newInstance();
    android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.frame, fragment);
    fragmentTransaction.addToBackStack("" + previousDrawerItemChecked).commit();
}

private void sub_about_fragment(){
    toolbar.setSubtitle(R.string.menu_about);
    Fragment fragment = AboutFragment.newInstance();
    android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.frame, fragment);
    fragmentTransaction.addToBackStack("" + previousDrawerItemChecked).commit();
}



@Override
protected void onResume() {
    super.onResume();
    //registerReceiver();
}

@Override
protected void onPause() {
    //LocalBroadcastManager.getInstance(this).unregisterReceiver(mRegistrationBroadcastReceiver);
    //isReceiverRegistered = false;
    super.onPause();
}

private void registerReceiver(){
    /*if(!isReceiverRegistered) {
        LocalBroadcastManager.getInstance(this).registerReceiver(mRegistrationBroadcastReceiver,
                new IntentFilter(Const.GCM_REGISTRATION_COMPLETE));
        isReceiverRegistered = true;
    }*/
}
/**
 * Check the device to make sure it has the Google Play Services APK. If
 * it doesn't, display a dialog that allows users to download the APK from
 * the Google Play Store or enable it in the device's system settings.
 */
private boolean checkPlayServices() {
    GoogleApiAvailability apiAvailability = GoogleApiAvailability.getInstance();
    int resultCode = apiAvailability.isGooglePlayServicesAvailable(this);
    if (resultCode != ConnectionResult.SUCCESS) {
        if (apiAvailability.isUserResolvableError(resultCode)) {
            apiAvailability.getErrorDialog(this, resultCode, PLAY_SERVICES_RESOLUTION_REQUEST)
                    .show();
        } else {
            Log.i(TAG, "This device is not supported.");
            finish();
        }
        return false;
    }
    return true;
}
}

activity_main.xml：

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:ads="http://schemas.android.com/apk/res-auto"
android:id="@+id/drawer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".MainActivity">

<LinearLayout
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical">
    <include
        android:id="@+id/toolbar"
        layout="@layout/toolbar"/>

    <FrameLayout
        android:id="@+id/frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </FrameLayout>
</LinearLayout>

<!--app:itemBackground="@color/primary"-->
<android.support.design.widget.NavigationView
    android:id="@+id/navigation_view"
    android:layout_height="match_parent"
    android:layout_width="wrap_content"
    android:layout_gravity="end"
    app:headerLayout="@layout/drawer_header"
    app:itemIconTint="@drawable/navview_selected"
    app:itemTextColor="@drawable/navview_selected"
    app:menu="@menu/drawer_menu"
    />
</android.support.v4.widget.DrawerLayout>

Answer 1

可能你会得到空指针异常，因为你在使用drawerlayout进行实例化之前

  

navigationView.setNavigationItemSelectedListener

在这里

  

drawerLayout.closeDrawers（）;

解决方案首先初始化drawerlayout

drawerLayout = (DrawerLayout) findViewById(R.id.drawer);

//Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

        // This method will trigger on item Click of navigation menu
        @Override
        public boolean onNavigationItemSelected(MenuItem menuItem) {


            //Checking if the item is in checked state or not, if not make it in checked state
            if(menuItem.isChecked()) menuItem.setChecked(false);
            else menuItem.setChecked(true);

            //Closing drawer on item click
            drawerLayout.closeDrawers();

            //Check to see which item was being clicked and perform appropriate action
            switch (menuItem.getItemId()){
                //Replacing the main content with ContentFragment Which is our Inbox View;
                case R.id.recently_added:
                    sub_recently_added();
                    previousDrawerItemChecked = 0;
                    return true;
                case R.id.categories:
                    sub_labels_results();
                    previousDrawerItemChecked = 1;
                    return true;
                case R.id.popular:
                    sub_label_results(Const.BLOGGER_FEATURED_CATEGORY);
                    previousDrawerItemChecked = 2;
                    return true;
                case R.id.about:
                    sub_about_fragment();
                    previousDrawerItemChecked = 3;
                    return true;
                case R.id.rate_app:
                    Uri uri = Uri.parse("market://details?id=" + getApplicationContext().getPackageName());
                    Intent goToMarket = new Intent(Intent.ACTION_VIEW, uri);
                    // To count with Play market backstack, After pressing back button,
                    // to taken back to our application, we need to add following flags to intent.
                    goToMarket.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY |
                            Intent.FLAG_ACTIVITY_NEW_DOCUMENT |
                            Intent.FLAG_ACTIVITY_MULTIPLE_TASK);
                    try {
                        startActivity(goToMarket);
                    } catch (ActivityNotFoundException e) {
                        startActivity(new Intent(Intent.ACTION_VIEW,
                                Uri.parse("http://play.google.com/store/apps/details?id=" + getApplicationContext().getPackageName())));
                    }
                    return true;
                default:
                    Toast.makeText(getApplicationContext(),"Somethings Wrong",Toast.LENGTH_SHORT).show();
                    return true;

            }
        }
    });