I am unable to set a submenu item as checked

问题

I am using a NavigationView for my drawer. This is the menus.xml file which defines all the menu items for the drawer:

<?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/item_1"
            android:title="Item 1"
            android:checked="true" />
        <item
            android:id="@+id/item_2"
            android:title="Item 2" />
        <item
            android:id="@+id/item_3"
            android:title="Item 3" />
        <item
            android:id="@+id/item_4"
            android:title="Item 4" />
        <item android:title="List 1">
            <menu>
                <item
                    android:id="@+id/subitem_1"
                    android:title="SubItem 1" />
                <item
                    android:id="@+id/subitem_2"
                    android:title="SubItem 2" />
            </menu>
        </item>
        <item android:title="List 2">
            <menu>
                <item
                    android:id="@+id/subitem_3"
                    android:title="SubItem 3" />
                <item
                    android:id="@+id/subitem_4"
                    android:title="SubItem 4" />
            </menu>
        </item>
    </group>
</menu>

Thing is when I call setChecked(true) on the sub menu items it doesn't get highlighted.

So if I force the attribute android:checkable="true" on the sub-menu items, it takes two clicks to have it highlighted. Also, as you can see Item 1 is highlighted and the checkableBehaviour is set to single. In this case, the sub menu and the first item remain highlighted. Why is the sub menu not getting highlighted on running setChecked(true)?

回答1:

For submenu should be added the group with android:checkableBehavior="single"

Your xml should be something like this:

<menu xmlns:android="http://schemas.android.com/apk/res/android">
<group android:checkableBehavior="single">
    <item
        android:id="@+id/item_1"
        android:checked="true"
        android:title="Item 1" />
    <item
        android:id="@+id/item_2"
        android:title="Item 2" />
    <item
        android:id="@+id/item_3"
        android:title="Item 3" />
    <item
        android:id="@+id/item_4"
        android:title="Item 4" />
    <item android:title="List 1">
        <menu>
            <group android:checkableBehavior="single">
                <item
                    android:id="@+id/subitem_1"
                    android:title="SubItem 1" />
                <item
                    android:id="@+id/subitem_2"
                    android:title="SubItem 2" />
            </group>
        </menu>
    </item>
    <item android:title="List 2">
        <menu>
            <group android:checkableBehavior="single">
                <item
                    android:id="@+id/subitem_3"
                    android:title="SubItem 3" />
                <item
                    android:id="@+id/subitem_4"
                    android:title="SubItem 4" />
            </group>
        </menu>
    </item>
</group>

回答2:

Maybe try doing it programmatially. Add this method if you have it already. The key part is the "menu.findItem(R.id.item_1).setChecked(true);"

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    super.onPrepareOptionsMenu(menu);
    menu.findItem(R.id.item_1).setChecked(true);
    return true;
}

回答3:

I will answer my own question. So the design library was released recently. And as such, it does not have the option yet to set a submenu item as checked. Nor does it have the ability to set items created within groups which is in turn wrapped by another group as checked. Guess, we will have to wait.

回答4:

I can set it to checked in the event listener where I get menuItem reference. But, you have to set this in XML for it to work:

android:checkable="true"

Now I can set it to checked state, but the display of it is broken (in my case) and I am fixing it, I will add info to this post later.

回答5:

Generalizing @jlga's answer:

You need to enclose all your item tags within a group tag and set the group's android:checkableBehavior attribute as single.

For instance, assume that you have the following menu arrangement,

<!-- Your previous sections here -->

<item android:title="New Section">
        <menu>

            <item
                android:id="@+id/one"
                android:title="1" />

            <item
                android:id="@+id/two"
                android:title="2" />

        </menu>
</item>

setChecked would have no effect on any item in this "New Section". Hence, to be able to do so, change it as follows:

<!-- Your previous sections here -->

<item android:title="New Section">
        <menu>
            <group android:checkableBehavior="single">
                <item
                    android:id="@+id/one"
                    android:title="1" />

                <item
                    android:id="@+id/two"
                    android:title="2" />

             </group>
        </menu>
</item>

来源：https://stackoverflow.com/questions/30922012/i-am-unable-to-set-a-submenu-item-as-checked

标签

android

menuitem