如何将MenuItem投射到LinearLayout [英] How to cast MenuItem to LinearLayout
问题描述
我有NavigationView
菜单.
我可以使用
从navigationView
获取MenuItem
I have NavigationView
with menus.
I am able to get MenuItem
from navigationView
by using
MenuItem menuItem = navigationView.getMenu().getItem(0);
LinearLayout linearLayout = (LinearLayout) menuItem;
我想将menuItem
投射到LinearLayout
或视图".
I want to cast menuItem
to LinearLayout
or View.
我已经在menu.xml中将android:actionViewClass
设置为menu
:
I have set android:actionViewClass
to menu
in menu.xml :
<item
android:id="@+id/nav_backup"
android:icon="@drawable/ic_sd_card_black_24dp"
android:actionViewClass="android.widget.LinearLayout"
android:title="@string/backup_configuration" />
在投射时,我面对NullPointerException
.我该如何投放?
While casting I am facing NullPointerException
. How can I cast this?
推荐答案
首先尝试对您的MenuItem
设置自定义布局,而不是像下面的代码一样将其强制转换为LinearLayout
Try this first set custom layout to your MenuItem
than cast it to LinearLayout
like below code
MenuItem item = menu.findItem(R.id.action_cart);
MenuItemCompat.setActionView(item, R.layout.menu_layout);
LinearLayout linearLayout = (LinearLayout) MenuItemCompat.getActionView(item);
编辑
直接使用 MenuItem.setActionView()
和 MenuItem.getActionView()
Direct use MenuItem.setActionView()
and MenuItem.getActionView()
示例代码
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuItem item = menu.findItem(R.id.action_menu);
item.setActionView( R.layout.activity_main);
LinearLayout linearLayout = (LinearLayout) item.getActionView();
return super.onCreateOptionsMenu(menu);
}
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