I have created MainActivity with NavigationView. When Activity is opened I want to automatically select the first item in the navigation drawer and open Fragment under that item. I've searched a lot but didn't find any proper solutions.
What is the proper way to do this ?
Main Activity:
public class MainActivity extends AppCompatActivity implements Config {
private NavigationView navigationView;
private DrawerLayout drawerLayout;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbar.setTitleTextColor(getResources().getColor(R.color.colorIcons));
if (null != getSupportActionBar())
getSupportActionBar().setLogo(R.drawable.ic_blogger_white);
//Start PostListFragmentWebView
/*PostListFragmentWebView postListFragmentWebView = new PostListFragmentWebView();
getSupportFragmentManager().beginTransaction()
.replace(R.id.frame, postListFragmentWebView)
.commit();*/
//Initializing NavigationView
navigationView = (NavigationView) findViewById(R.id.navigationView);
//Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(MenuItem menuItem) {
//Checking if the item is in checked state or not, if not set it to 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 clicked and perform the appropriate action.
switch (menuItem.getItemId()) {
case R.id.posts:
PostListFragmentWebView postListFragment = new PostListFragmentWebView();
getSupportFragmentManager().beginTransaction()
.replace(R.id.frame, postListFragment)
.commit();
return true;
case R.id.pages:
PageListFragmentWebView pagetListFragment = new PageListFragmentWebView();
getSupportFragmentManager().beginTransaction()
.replace(R.id.frame, pagetListFragment)
.commit();
return true;
case R.id.blog:
BlogInfoFragmentWebView blogInfoFragment = new BlogInfoFragmentWebView();
getSupportFragmentManager().beginTransaction()
.replace(R.id.frame, blogInfoFragment)
.commit();
return true;
default:
Toast.makeText(getApplicationContext(), getResources().getString(R.string.drawer_error), Toast.LENGTH_SHORT).show();
return true;
}
}
});
// Initializing Drawer Layout and ActionBarToggle
drawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.open_drawer, R.string.close_drawer) {
@Override
public void onDrawerClosed(View drawerView) {
// Code here will be triggered once the drawer closes as we don't 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);
drawerLayout.getChildAt(0).setSelected(true);
//calling sync state is necessary or else your hamburger icon wont show up
actionBarDrawerToggle.syncState();
}
}
In onCreate(), following code will load the first item's fragment upon first start:
if (savedInstanceState == null) {
navigationView.getMenu().performIdentifierAction(R.id.posts, 0);
}
Thanks to calvinfly for this comment.
Add android:checked="true" to your first menu item.
And manually select one item, using
getSupportFragmentManager().beginTransaction().replace(R.id.frame, postListFragment).commit();
to open fragment.
Instead of normal listener ...
navView.setNavigationItemSelected(new Navigation.View.OnNavigationItemSelectedListener() {bla, bla, bla})
Create the listener as an Obj:
NavigationView.OnNavigationItemSelectedListener navViewListener;
navView.setNavigationItemSelectedListener(navViewListener = new NavigationView.OnNavigationItemSelectedListener() {bla, bla, bla})
...and use the Obj to trigger the listener event:
navViewListener.onNavigationItemSelected(navView.getMenu().getItem(0));
...where getItem(0) is the first menu item.
Use a method getItem(0).setChecked(true) or android:checked="true" at its menu item XML definition.
You could also use navigationView.setCheckedItem(R.id.default)(javadoc) after you setup your navigationview.
just add this code in onCreate method:
FragmentTransaction ftrans = getFragmentManager().beginTransaction();
ftrans.replace(R.id.container, <yourfragment>).commit();
Work for me !
This can be done even better while considering orientation and other configuration changes. We could select whatever nav drawer menuitem depending on whether we are coming from a previous state. Check: For the Navigation drawer wielding Activity:-
public static final String SELECTED_NAV_MENU_KEY = "selected_nav_menu_key";
// The selected grid position
private int mSelectedNavMenuIndex = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_demo);
...........................................................
navigationView.setNavigationItemSelectedListener(this);
if (savedInstanceState != null) {
// Recover assets
mSelectedNavMenuIndex = savedInstanceState.getInt(SELECTED_NAV_MENU_KEY);
// Recover menu as selected
MenuItem menuItem = navigationView.getMenu().getItem(mSelectedNavMenuIndex);
toggleNavMenuItemCheck(menuItem);
navigationView.getMenu().performIdentifierAction(menuItem.getItemId(), mSelectedNavMenuIndex);
return;
} else {
MenuItem menuItem = navigationView.getMenu().getItem(mSelectedNavMenuIndex);
toggleNavMenuItemCheck(menuItem);
navigationView.getMenu().performIdentifierAction(menuItem.getItemId(), mSelectedNavMenuIndex);
}
}
The toggle method that helps uncheck or check the menu item
private void toggleNavMenuItemCheck(MenuItem menuItem) {
if (menuItem.isChecked()){
menuItem.setChecked(false);
} else {
menuItem.setChecked(true);
}
}
This is how I save the state of the selected menu item. Check:-
@Override
public boolean onNavigationItemSelected(MenuItem item) {
int id = item.getItemId();
switch (id) {
case R.id.nav_explore:
showExploreFragment(null);
mSelectedNavMenuIndex = 0;
break;
case R.id.nav_orders:
mSelectedNavMenuIndex = 1;
break;
case R.id.nav_settings:
mSelectedNavMenuIndex = 2;
break;
default:
showExploreFragment(null);
mSelectedNavMenuIndex = 0;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}
// Save any important data for recovery
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(SELECTED_NAV_MENU_KEY, mSelectedNavMenuIndex);
}
NB: The line with code:
navigationView.getMenu().performIdentifierAction(menuItem.getItemId(), mSelectedNavMenuIndex);
Can be replaced by the code:
onNavigationItemSelected(menuItem);
in menu.xml remember to mention android:checkable="true" for single item and android:checkableBehavior="single" for a group of items.
<item
android:id="@+id/pos_item_help"
android:checkable="true"
android:title="Help" />
<group
android:id="@+id/group"
android:checkableBehavior="single">
<item
android:id="@+id/menu_nav_home"
android:icon="@drawable/ic_home_black_24dp"
android:title="@string/menu_nav_home" />
</group>
then inside NavigationItemSelectedListener use setCheckedItem(R.id.item_id_in_menu) to make it selected.
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.pos_item_pos:
navigationView.setCheckedItem(R.id.pos_item_pos);
break;
case R.id.pos_item_orders:
navigationView.setCheckedItem(R.id.pos_item_orders);
break;
default:
}
return true;
}
And you do not have to do the dirty task of managing the selected item anymore. navigationView manages it by self.
1.) To land to the HomeFragment initially, use this inside your onCreate() in MainActivity:
Fragment fragment = new HomeFragment();
// replacing the fragment
if (fragment != null) {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.content_frame, fragment);
ft.commit();
}
2.) To set the item as selected in navigationDrawer set the item as checked in navigation_menu.xml
android:checked = "true"
来源：https://stackoverflow.com/questions/31043219/how-to-select-the-first-item-in-a-navigation-drawer-and-open-a-fragment-on-appli