How to set shared checkable behavior across all gr

问题:

I've created two groups with unique ids (I need a divider) and they both have checkableBehavior set to single. This allows multiple items from different groups to be checked at once, and that's exactly what I'm trying to avoid. I'd like to have one item checked at maximum, across all groups.

Since I haven't found any way to do this in XML, I tried to implement a simple logic in onNavigationItemSelected to uncheck the previous menu item:

if (previousItem != null)
   previousItem.setChecked(false);
currentItem.setChecked(true);

but setChecked(false) method has never worked for me - the item stays checked.

Here's my sample code:

menu_navigation.xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android">
<group
        android:id="@+id/nav_group_1"
        android:checkableBehavior="single">
    <item
            android:id="@+id/nav_feed"
            android:title="@string/feed"/>
    <item
            android:id="@+id/nav_people"
            android:title="@string/people"/>
</group>
<group
        android:id="@+id/nav_group_2"
        android:checkableBehavior="single">
    <item
            android:id="@+id/nav_settings"
            android:title="@string/settings"/>
    <item
            android:id="@+id/nav_help_feedback"
            android:title="@string/help_feedback"/>
    <item
            android:id="@+id/nav_logout"
            android:title="@string/logout"/>
</group>

NavigationItemSelectedListener:

 mUiNavigationView.setNavigationItemSelectedListener(
                new NavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(MenuItem menuItem) {
                        if (previousItem != null)
                           previousItem.setChecked(false);
                        currentItem.setChecked(true);
                        //...
                        changeCurrentFragment(...);
                        return true;
                    }
                });

I need a hint! Thanks.

回答1:

Here's the solution.

Step 1: Remove

android:checkableBehavior="single"

from both groups.

Step 2: Add the following logic to the listener:

mUiNavigationView.setNavigationItemSelectedListener(
            new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem menuItem) {
                    menuItem.setCheckable(true);
                    menuItem.setChecked(true);
                    if (mPreviousMenuItem != null) {
                        mPreviousMenuItem.setChecked(false);
                    }
                    mPreviousMenuItem = menuItem;
                    //...
                    changeCurrentFragment(...);
                    return true;
                }
            });

Note: instead of calling menuItem.setCheckable(true) you can set android:checkable="true" for each item in XML.

@Moinkhan's solution should work as well (thanks, upvoted), but I didn't want to loop through menu's items each time a new position is selected.

回答2:

Actually, you don't need separate parallel groups for separators. You can have everything in one group and place submenus (have titles) or subgroups (no title) in it. There will be separators for those submenus and subgroups. This way the checkable behavior works without a workaround. (Fyi: This is on Design Support Lib 23.1.1)

<group
    android:id="@+id/drawer_group"
    android:checkableBehavior="single">
    <item
        android:id="@+id/nav_1"
        android:title="Menu1" />
    <item
        android:id="@+id/nav_2"
        android:title="Menu2" />
    <item
        android:id="@+id/nav_3"
        android:title="Menu3" />
    <item
        android:id="@+id/nav_4"
        android:title="Menu4" />

    <item
        android:id="@+id/drawer_submenu"
        android:title="Subheader">
        <menu>
            <group android:checkableBehavior="single">
                <item
                    android:id="@+id/nav_sub1_1"
                    android:title="Menu_Sub1_1" />
                <item
                    android:id="@+id/nav_sub1_2"
                    android:title="Menu_Sub1_2" />
            </group>
        </menu>
    </item>

    <group android:id="@+id/drawer_subgroup">
        <item
            android:id="@+id/nav_subgroup_item"
            android:title="Menu_Sub2_2" />
    </group>
</group>

In code, I simply do the following and single checking works as expected:

@Override
public boolean onNavigationItemSelected(MenuItem item) {
    mNavigationView.setCheckedItem(item.getItemId());
    ...
}

回答3:

No need to remove checkableBehavior="single", just use

navigationView.setCheckedItem(item.getItemId());

instead of item.setChecked(true).

回答4:

Ok I found the solution .. just add this snippet code to onNavigationItemSelected method

@Override
    public boolean onNavigationItemSelected(MenuItem menuItem) {
    Menu m = navView.getMenu();
    for (int i=0;i<m.size();i++) {
        MenuItem mi = m.getItem(i);
        if (!(mi.getItemId() == menuItem.getItemId())) {
            mi.setCheckable(false);
        }
    }
    menuItem.setCheckable(true);
    menuItem.setChecked(true);
    return false;
}

that's it .. And yes setChecked(false) not working. Just because from list of menu there should be a one single item must be cheked. So you can only uncheck it when you select another item .. And if you click on selected item, the navigationview will never unchecked it. Just because the scenario i have explaind.

回答5:

There appears to be an invalidation bug in the NavigationView implementation, but you don't need to use setCheckable(), you just need to invalidate the NavigationView after calling setChecked(false), like so:

    previousItem.setChecked(false);
    navigationView.invalidate();

However the menu group must not have checkableBehavior="single", because in exclusive mode calling setChecked(boolean) on a MenuItem in the group will set that item as checked whether you pass true or false. So in order for setChecked(false) to work, you must remove checkableBehavior="single" from your menu definitions.

I created an issue about this here: https://code.google.com/p/android/issues/detail?id=178709

回答6:

Here's a simple and sweet solution i posted here:)

Making different groups does make a divider in between But creates the problem of two checked items in the nav drawer.

A simple way how I handled this was:

 public boolean onNavigationItemSelected(final MenuItem menuItem) {

//if an item from extras group is clicked,refresh NAV_ITEMS_MAIN to remove previously checked item
if (menuItem.getGroupId() == NAV_ITEMS_EXTRA) {


    navigationView.getMenu().setGroupCheckable(NAV_ITEMS_MAIN, false, true);
    navigationView.getMenu().setGroupCheckable(NAV_ITEMS_EXTRA, true, true);
   }else{

    navigationView.getMenu().setGroupCheckable(NAV_ITEMS_MAIN, true, true);
    navigationView.getMenu().setGroupCheckable(NAV_ITEMS_EXTRA, false, true);


}
//Update highlighted item in the navigation menu
menuItem.setChecked(true);

}