android开发时华为手机底部导航栏挡住了应用布局

原因：使用安卓的BottomNavigationView控件开发底部导航栏同时使用了沉浸式状态栏导致华为手机的底部导航栏会盖住我应用的导航栏。

解决：先写一个工具类

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
 
import java.lang.reflect.Method;
 
public class NavigationBarUtil {
    public static void initActivity(View content) {
        new NavigationBarUtil(content);
    }
 
    private View mObserved;//被监听的视图
    private int usableHeightView;//视图变化前的可用高度
    private ViewGroup.LayoutParams layoutParams;
 
    private NavigationBarUtil(View content) {
        mObserved = content;
        //给View添加全局的布局监听器监听视图的变化
        mObserved.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            public void onGlobalLayout() {
                resetViewHeight();
            }
        });
        layoutParams = mObserved.getLayoutParams();
    }
 
    /**
     * 重置视图的高度，使不被底部虚拟键遮挡
     */
    private void resetViewHeight() {
        int usableHeightViewNow = CalculateAvailableHeight();
        //比较布局变化前后的View的可用高度
        if (usableHeightViewNow != usableHeightView) {
            //如果两次高度不一致
            //将当前的View的可用高度设置成View的实际高度
            layoutParams.height = usableHeightViewNow;
            mObserved.requestLayout();//请求重新布局
            usableHeightView = usableHeightViewNow;
        }
    }
 
    /**
     * 计算试图高度
     * @return
     */
    private int CalculateAvailableHeight() {
        Rect r = new Rect();
        mObserved.getWindowVisibleDisplayFrame(r);
        return (r.bottom - r.top);//如果不是沉浸状态栏，需要减去顶部高度
//        return (r.bottom );//如果是沉浸状态栏
    }
 
    /**
     * 判断底部是否有虚拟键
     * @param context
     * @return
     */
    public static boolean hasNavigationBar(Context context) {
        boolean hasNavigationBar = false;
        Resources rs = context.getResources();
        int id = rs.getIdentifier("config_showNavigationBar", "bool", "android");
        if (id > 0) {
            hasNavigationBar = rs.getBoolean(id);
        }
        try {
            Class systemPropertiesClass = Class.forName("android.os.SystemProperties");
            Method m = systemPropertiesClass.getMethod("get", String.class);
            String navBarOverride = (String) m.invoke(systemPropertiesClass, "qemu.hw.mainkeys");
            if ("1".equals(navBarOverride)) {
                hasNavigationBar = false;
            } else if ("0".equals(navBarOverride)) {
                hasNavigationBar = true;
            }
        } catch (Exception e) {
 
        }
        return hasNavigationBar;
 
    }
 
}

然后在activity的OnCreate方法中写入下面的代码：

if(NavigationBarUtil.hasNavigationBar(this)){
            NavigationBarUtil.initActivity(findViewById(android.R.id.content));
        }