Android BottomNavigationView添加角标

BottomNavigationView角标效果图.png

插入角标代码：

    @SuppressLint("RestrictedApi")
    private void setBNV_Badge(int position, int num) {
        if (num <= 0) {
            return;
        }
        BottomNavigationMenuView menuView = (BottomNavigationMenuView) mBinding.bnv.getChildAt(0);
        if (null == menuView) {
            return;
        }
        if (position > menuView.getChildCount() - 1) {
            return;
        }
        BottomNavigationItemView itemView = (BottomNavigationItemView) menuView.getChildAt(position);
        View badge = LayoutInflater.from(this).inflate(R.layout.layout_badge, itemView, false);
        TextView numView = badge.findViewById(R.id.tv_badge_num);
        UnreadMsgUtil.show(numView, num);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT);
        lp.leftMargin = menuView.getItemIconSize();
        lp.bottomMargin = SizeUtils.dp2px(28);//BottomNavigationView的高度为50dp
        itemView.addView(badge, lp);
    }

调用代码：

        setBNV_Badge(0, 1);
        setBNV_Badge(1, 100);
        setBNV_Badge(2, 0);

角标布局xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/tv_badge_num"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/bg_ff2a39"
        android:gravity="center"
        android:layout_gravity="center"
        android:minWidth="@dimen/dp_15"
        android:minHeight="@dimen/dp_15"
        android:textColor="@color/color_FFFFFF"
        android:visibility="visible"
        android:textSize="@dimen/sp_8"
        tools:text="99+" />
</FrameLayout>

UnreadMsgUtil代码：

/**
 * ================================
 * Des:未读角标工具类
 * Created by kele on 2021/2/25.
 * E-mail:984127585@qq.com
 * ================================
 */
public class UnreadMsgUtil {

    public static void show(TextView numView, int num) {
        if (numView == null) {
            return;
        }
        ViewGroup.LayoutParams lp = numView.getLayoutParams();
        DisplayMetrics dm = numView.getResources().getDisplayMetrics();
        numView.setVisibility(View.VISIBLE);
        if (num > 0 && num < 10) {//圆
            lp.width = (int) (15 * dm.density);
            numView.setText(num + "");
        } else if (num > 9 && num < 100) {//圆角矩形,圆角是高度的一半,设置默认padding
            lp.width = RelativeLayout.LayoutParams.WRAP_CONTENT;
            numView.setPadding((int) (6 * dm.density), 0, (int) (6 * dm.density), 0);
            numView.setText(num + "");
        } else {//数字超过两位,显示99+
            lp.width = RelativeLayout.LayoutParams.WRAP_CONTENT;
            numView.setPadding((int) (6 * dm.density), 0, (int) (6 * dm.density), 0);
            numView.setText("99+");
        }
        numView.setLayoutParams(lp);
    }
}

dp2px代码：

    public static int dp2px(final float dpValue) {
        final float scale = Resources.getSystem().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }

参考链接：

https://blog.csdn.net/a_zhon/article/details/78334515