效果
思路
獲取整個BottomNavigationView菜單,再根據下標獲取某一個子菜單tab,然後給這個tab添加我們自定義的view,可以是數字也可以是文字。
代碼
/**
* 給BottomNavigationView 設置Badge 小紅點
*
* BottomNavigationMenuView中的每一個Tab是一個FrameLayout,所以可以在上面隨意添加View、這樣就可以實現角標了
*/
private fun setBadge() {
//獲取底部菜單view
val menuView = bottom_navigation.getChildAt(0) as BottomNavigationMenuView
//獲取第2個itemView
val itemView = menuView.getChildAt(1) as BottomNavigationItemView
//引入badgeView
val badgeView = LayoutInflater.from(this).inflate(R.layout.layout_badge_view, menuView, false)
//把badgeView添加到itemView中
itemView.addView(badgeView)
//獲取子view並設置顯示數目
val count = badgeView.findViewById<TextView>(R.id.tv_badge)
count.text = "2"
//不顯示則隱藏
//count.visibility=View.GONE
}
layout_badge_view就是自定義的一個layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="@+id/tv_badge"
android:layout_width="@dimen/dp_18"
android:layout_height="@dimen/dp_18"
android:layout_gravity="center"
android:layout_marginLeft="@dimen/dp_10"
android:layout_marginTop="@dimen/dp_2"
android:background="@drawable/shape_oval_primary"
android:gravity="center"
android:includeFontPadding="false"
android:text="1"
android:textColor="@color/white" />
</LinearLayout>
shape_oval_primary是一個背景爲主題色的圓
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="oval"
android:useLevel="false">
<solid android:color="@color/colorPrimary" />
<stroke
android:width="0dp"
android:color="@color/white" />
<size
android:width="10dp"
android:height="10dp" />
</shape>