Android 全面屏下開啟底部虛擬導(dǎo)航按鈕時(shí)界面被遮擋的問題

???????目前大家手里握的都是全面屏的手機(jī)，而且每家廠商都對全面屏的手機(jī)做了手勢的支持確實(shí)是從體驗(yàn)上得到了很大的提升季春，再也不是當(dāng)年16:9的屏底部再配個(gè)三大金剛的導(dǎo)航按鈕使得有限的可是預(yù)覽面積更小了厘唾。但是2020年依然會(huì)有人不使用全面屏手勢選擇三大金剛的導(dǎo)航按鈕，這就引出了今天的問題萝风。

癥狀：開啟底部虛擬導(dǎo)航按鈕橘忱，進(jìn)入全屏顯示的頁面，此頁面有輸入框铣缠，這時(shí)發(fā)現(xiàn)底部被遮擋的問題

使用全面屏手勢.jpeg

使用導(dǎo)航按鈕.jpeg

看到全屏顯示烘嘱、界面上還有輸入框，大家肯定會(huì)想到鍵盤彈出遮擋的bug,還有這個(gè)AndroidBug5497Workaround類（如有沒使用過的小伙伴代碼貼到下面）

public class AndroidBug5497Workaround {


    // For more information, see https://code.google.com/p/android/issues/detail?id=5497
    // To use this class, simply invoke assistActivity() on an Activity that already has its content view set.

    public static void assistActivity (Activity activity) {
        new AndroidBug5497Workaround(activity);
    }

    private View mChildOfContent;
    private int usableHeightPrevious;
    private FrameLayout.LayoutParams frameLayoutParams;

    private AndroidBug5497Workaround(final Activity activity) {
        FrameLayout content = (FrameLayout) activity.findViewById(android.R.id.content);
        mChildOfContent = content.getChildAt(0);
        mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            public void onGlobalLayout() {
                possiblyResizeChildOfContent(activity);
            }
        });
        frameLayoutParams = (FrameLayout.LayoutParams) mChildOfContent.getLayoutParams();
    }

    private void possiblyResizeChildOfContent(Activity activity) {
        int usableHeightNow = computeUsableHeight() ;
        if (usableHeightNow != usableHeightPrevious) {

            int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
            int heightDifference = usableHeightSansKeyboard - usableHeightNow;
            if (heightDifference > (usableHeightSansKeyboard/4)) {
                // keyboard probably just became visible
                frameLayoutParams.height = usableHeightSansKeyboard - heightDifference;
            } else {
                // keyboard probably just became hidden
                frameLayoutParams.height = usableHeightSansKeyboard;
            }
            mChildOfContent.requestLayout();
            usableHeightPrevious = usableHeightNow;
        }
    }

    private int computeUsableHeight() {
        Rect r = new Rect();
        mChildOfContent.getWindowVisibleDisplayFrame(r);
        return (r.bottom - r.top);// 全屏模式下： return r.bottom
    }
}

我們今天講的這個(gè)問題蝗蛙，其實(shí)也是要從這個(gè)類來修改

1590656854230.jpg

問題就是我們沒有去掉底部導(dǎo)航按鈕的高度
這個(gè)導(dǎo)航欄的高度怎么計(jì)算呢蝇庭？
大部分人會(huì)想到拿屏幕的實(shí)際高度減去當(dāng)前可用的高度不就是底部按鈕的高度嗎，我一開始也是這么想的捡硅，沒啥大毛病哮内，然后就是一頓擼

/**
     * 獲取屏幕高度
     * @param context
     * @return
     */
    public static int getScreeHeight(Context context) {
        return context.getResources().getDisplayMetrics().heightPixels;
    }

    /**
     * 獲取屏幕寬度
     * @param context
     * @return
     */
    public static int getScreeWidth(Context context) {
        return context.getResources().getDisplayMetrics().widthPixels;
    }

    /**
     * 獲取實(shí)際高度
     * @param context
     * @return
     */
    public static int getScreeRealHeight(Context context) {
        Display display = getDisplay(context);
        if (display == null) {
            return 0;
        }
        DisplayMetrics dm = new DisplayMetrics();
        display.getRealMetrics(dm);
        return dm.heightPixels;
    }

    /**
     * 獲取實(shí)際寬度
     * @param context
     * @return
     */
    public static int getScreeRealWidth(Context context) {
        Display display = getDisplay(context);
        if (display == null) {
            return 0;
        }
        DisplayMetrics dm = new DisplayMetrics();
        display.getRealMetrics(dm);
        return dm.widthPixels;
    }

    private static Display getDisplay(Context context) {
        WindowManager wm;
        if (context instanceof Activity) {
            Activity activity = (Activity) context;
            wm = activity.getWindowManager();
        } else {
            wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        }
        if (wm != null) {
            return wm.getDefaultDisplay();
        }
        return null;
    }

三星手機(jī)測試ok 正想結(jié)束戰(zhàn)斗時(shí)。拿一加手機(jī)一測試 bug又回來了
所以這種方式獲取底部按鈕高度是存在兼容性的
最終給出小伙伴們具有兼容性的底部按鈕高度的獲茸尘隆：分兩種情況全面屏和非全面屏的獲取
1. 全面屏下
* 1.1 開啟全面屏開關(guān)->返回0
* 1.2 關(guān)閉全面屏開關(guān)-> 執(zhí)行非全面屏下處理方式
2. 非全面屏下
* 2.1 沒有虛擬鍵->返回0
* 2.1 虛擬鍵隱藏->返回0
* 2.2 虛擬鍵存在且未隱藏-返回虛擬鍵實(shí)際高度

public static int getNavigationBarHeightIfRoom(Context context) {
        if(navigationGestureEnabled(context)){
            return 0;
        }
        return getCurrentNavigationBarHeight(((Activity) context));
    }

    /**
     * 全面屏（是否開啟全面屏開關(guān) 0 關(guān)閉  1 開啟）
     *
     * @param context
     * @return
     */
    public static boolean navigationGestureEnabled(Context context) {
        int val = Settings.Global.getInt(context.getContentResolver(), getDeviceInfo(), 0);
        return val != 0;
    }

    /**
     * 獲取設(shè)備信息（目前支持幾大主流的全面屏手機(jī)北发，親測華為、小米喷屋、oppo琳拨、魅族、vivo都可以）
     *
     * @return
     */
    public static String getDeviceInfo() {
        String brand = Build.BRAND;
        if(TextUtils.isEmpty(brand)) return "navigationbar_is_min";

        if (brand.equalsIgnoreCase("HUAWEI")) {
            return "navigationbar_is_min";
        } else if (brand.equalsIgnoreCase("XIAOMI")) {
            return "force_fsg_nav_bar";
        } else if (brand.equalsIgnoreCase("VIVO")) {
            return "navigation_gesture_on";
        } else if (brand.equalsIgnoreCase("OPPO")) {
            return "navigation_gesture_on";
        } else {
            return "navigationbar_is_min";
        }
    }

    /**
     * 非全面屏下 虛擬鍵實(shí)際高度(隱藏后高度為0)
     * @param activity
     * @return
     */
    public static int getCurrentNavigationBarHeight(Activity activity){
        if(isNavigationBarShown(activity)){
            return getNavigationBarHeight(activity);
        } else{
            return 0;
        }
    }

    /**
     * 非全面屏下 虛擬按鍵是否打開
     * @param activity
     * @return
     */
    public static boolean isNavigationBarShown(Activity activity){
        //虛擬鍵的view,為空或者不可見時(shí)是隱藏狀態(tài)
        View view  = activity.findViewById(android.R.id.navigationBarBackground);
        if(view == null){
            return false;
        }
        int visible = view.getVisibility();
        if(visible == View.GONE || visible == View.INVISIBLE){
            return false ;
        }else{
            return true;
        }
    }

    /**
     * 非全面屏下 虛擬鍵高度(無論是否隱藏)
     * @param context
     * @return
     */
    public static int getNavigationBarHeight(Context context){
        int result = 0;
        int resourceId = context.getResources().getIdentifier("navigation_bar_height","dimen", "android");
        if (resourceId > 0) {
            result = context.getResources().getDimensionPixelSize(resourceId);
        }
        return result;
    }

到此一連串的問題就解決了Ｍ筒堋Ｓ印！