问题
I have a DrawerLayout enclosing a NavigationView and this layout activity serves as a common Navigation drawer for all the activities in my app. I am providing the menu resource for app:menu in navigation view. I have some menu items, but I want one menu item to be collapsible/expandable, so that when I click on it, it expands to show two submenus and collapses again on a second click.
I have added submenus by adding another <menu> inside the <item> but cant make it collapsible/expandable.
Additionally, I don't want to use ExpandableListView for my purpose. Instead, I just need to do some tweaks in menu resource file. Please just point me in the correct direction. I have searched Google only to find code, blogs, and examples for collapsible list items using ExpandableListView, but I need it to work with the NavigationView design widget from the design support Library.
Here's my code for the menu file:
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<group android:checkableBehavior="single">
<item
android:id="@+id/nav_aboutus"
android:title="About Us" />
<item
android:id="@+id/nav_faq"
android:title="FAQs" />
<item
android:id="@+id/nav_share"
android:title="Share" />
<item
android:id="@+id/nav_myaccount"
android:title="My Account" />
<item
android:id="@+id/nav_legal"
android:title="Legal" >
<menu>
<item
android:id="@+id/nav_tnc"
android:title="Terms and Conditions" />
<item
android:id="@+id/nav_pp"
android:title="Privacy Policy" />
</group>
</menu>
</item>
</menu>
I want Legal menu item to be expandable having two submenu items 'Terms and Conditions', 'Privacy Policy'.
回答1:
You can use expandable list views inside navigation drawers, I don't understand why you don't want to use them. More on that can be found here http://developer.android.com/reference/android/widget/ExpandableListView.html
If you insist on not using expandableListView, then the alternative is to design the expansion yourself using the menu's OnSelect for that specific item. Though I really don't know why you want this, you'd just be re-implementing the wheel.
回答2:
there is a trick to do this without using ExpandableListView.Add those menu items normally in menu layout file and hide/show them on item click of menu item under which you want to show them like this:
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
NavigationView nv= (NavigationView) findViewById(R.id.nav_view);
Menu m=nv.getMenu();
int id = item.getItemId();
if (id == R.id.nav_posts) {
boolean b=!m.findItem(R.id.nav_class).isVisible();
//setting submenus visible state
m.findItem(R.id.nav_class).setVisible(b);
m.findItem(R.id.nav_dept).setVisible(b);
m.findItem(R.id.nav_batch).setVisible(b);
m.findItem(R.id.nav_campus).setVisible(b);
return true;
} else if (id == R.id.nav_walls) {
boolean b=!m.findItem(R.id.nav_wall_events).isVisible();
//setting submenus visible state
m.findItem(R.id.nav_wall_events).setVisible(b);
m.findItem(R.id.nav_wall_fun).setVisible(b);
m.findItem(R.id.nav_wall_hadith).setVisible(b);
m.findItem(R.id.nav_wall_news).setVisible(b);
m.findItem(R.id.nav_wall_Poetry).setVisible(b);
return true;
} else if (id == R.id.nav_com) {
m.findItem(R.id.nav_share).setVisible(false);
m.findItem(R.id.nav_send).setVisible(false);
} else if (id == R.id.nav_share) {
} else if (id == R.id.nav_send) {
}
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
where menu layout file is:
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<group android:checkableBehavior="single">
<item
android:id="@+id/nav_posts"
android:icon="@drawable/ic_menu_camera"
android:title="Posts" />
<item
android:id="@+id/nav_class"
android:title="Class"
android:visible="false" />
<item
android:id="@+id/nav_dept"
android:title="Department"
android:visible="false" />
<item
android:id="@+id/nav_batch"
android:title="Batch"
android:visible="false" />
<item
android:id="@+id/nav_campus"
android:title="Campus"
android:visible="false" />
<item
android:id="@+id/nav_walls"
android:icon="@drawable/ic_menu_gallery"
android:title="Walls" />
<item
android:id="@+id/nav_wall_news"
android:title="News"
android:visible="false" />
<item
android:id="@+id/nav_wall_events"
android:title="Events"
android:visible="false" />
<item
android:id="@+id/nav_wall_fun"
android:title="Fun"
android:visible="false" />
<item
android:id="@+id/nav_wall_hadith"
android:title="Hadith"
android:visible="false" />
<item
android:id="@+id/nav_wall_Poetry"
android:title="Poetry"
android:visible="false" />
</group>
<item
android:id="@+id/nav_com"
android:title="Communicate">
<menu>
<item
android:id="@+id/nav_share"
android:icon="@drawable/ic_menu_share"
android:title="Share" />
<item
android:id="@+id/nav_send"
android:icon="@drawable/ic_menu_send"
android:title="Send" />
</menu>
</item>
</menu>
回答3:
In menu layout file:
<item
android:title="Setup"
android:id="@+id/SetupGr"
android:icon="@drawable/setup"
/>
<group
android:checkableBehavior="none"
android:id="@+id/SetupGroup">
<item
android:id="@+id/setupOutdoor"
android:icon="@drawable/outdoor"
android:title="Outdoor" />
<item
android:id="@+id/setupClocks"
android:icon="@drawable/ic_launcher"
android:title="Clocks" />
<item
android:id="@+id/selectMaps"
android:icon="@drawable/map"
android:title="Select map" />
</group>
In MyActivity.java - load desired menu:
public void LoadNavMenu(int iMenu){
navigationView.getMenu().clear();
navigationView.inflateMenu(iMenu);
navigationView.getMenu().setGroupVisible(R.id.HelpGroup,false);
navigationView.getMenu().setGroupVisible(R.id.SetupGroup,false);
}
And OnNavigationItemSelected:
public boolean onNavigationItemSelected(MenuItem item) {
// Handle navigation view item clicks here.
int id = item.getItemId();
navigationView.getMenu().setGroupVisible(R.id.HelpGroup,false);
navigationView.getMenu().setGroupVisible(R.id.SetupGroup,false);
switch (item.getItemId()){
case R.id.HelpGr:
navigationView.getMenu().setGroupVisible(R.id.HelpGroup,true);
navigationView.getMenu().setGroupVisible(R.id.SetupGroup,false);
return true;
case R.id.SetupGr:
navigationView.getMenu().setGroupVisible(R.id.SetupGroup,true);
navigationView.getMenu().setGroupVisible(R.id.HelpGroup,false);
return true;
}
base.closeDrawer(GravityCompat.START);
return true;
}
I have 1 item - Setup - and when user select it - I set Group with id - SetupGroup - visible and return without closing drawer. Else - I set all groups invisible.
来源：https://stackoverflow.com/questions/35956789/how-to-add-a-collapsible-menu-item-inside-navigation-drawer-in-android