为什么Android BottomNavigationView没有出现？

Question

我正在使用新的Android BottomNavigationView但底部导航MenuItem操作视图未显示.

调试后,我发现菜单项不为null,可见性可见.

在检查根视图的高度和宽度之后,即使在对布局layout_width=50dp和layout_height=50dp根元素中的值进行硬编码之后它也会变为0 .

这是我的底部导航菜单:

<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">

<item
    android:id="@+id/nearby_fragment"
    android:enabled="true"
    android:icon="@drawable/homenearbyfragment"
    android:title="@string/bottom_nearby"
    app:showAsAction="always"/>

<item
    android:id="@+id/route_fragment"
    android:title="@string/bottom_homescreen"
    android:enabled="true"
    app:showAsAction="always"
    android:icon="@drawable/home_mycommute" />

<item
    android:id="@+id/newsfeed_activity"
    android:title="@string/bottom_news"
    android:enabled="true"
    app:showAsAction="always"
    android:icon="@drawable/newsfeed"
    app:actionLayout="@layout/bagde_layout"/>

</menu>

我的动作布局:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
style="?android:attr/actionButtonStyle"
android:layout_width="50dp"
android:layout_height="50dp"
android:clickable="true"
android:focusable="true"
android:gravity="center">

<ImageView
    android:id="@+id/menu_badge_icon"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/newsfeed" />

<TextView
    android:id="@+id/menu_badge"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="top|end"
    android:layout_marginTop="4dp"
    android:background="@drawable/circle_bg"
    android:gravity="center"
    android:textColor="@android:color/white"
    android:textSize="8sp"
    />

在我Activity我试图设置:

private void setCountOnNews(Menu menu) {
    mReportMenu = menu.findItem(R.id.newsfeed_activity);
    FrameLayout count = (FrameLayout) mReportMenu.getActionView();
    count.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(MainActivity.this, NewsFeedActivity.class);
            startActivity(intent);
            MainApplication.getInstance().trackScreenView(getString(R.string.tracknewsfeedmenu));
        }
    });
    TextView notifCount = (TextView) count.findViewById(R.id.menu_badge);
    //if (Utils.getNewsfeedCountPreference(MainActivity.this) > 0)
    notifCount.setText(String.valueOf(Utils.getNewsfeedCountPreference(MainActivity.this)));
    notifCount.setText("asd;jfnapsdifnaspdifnasdpifnaspdfnapsdifnaspidfnapsidfnaspdiufif");
    Log.d(TAG, "setCountOnNews:" + notifCount.getText().toString());
    //else
    //  notifCount.setVisibility(View.GONE);
}

Answer 1

如果您使用的是片段，则需要将选项菜单设置为 true。

setHasOptionsMenu(true);