之前写过一遍6.0的导航栏屏蔽分析过程，可参考Android6.0 源码修改之屏蔽导航栏虚拟按键（Home和RecentAPP）/动态显示和隐藏NavigationBar

屏蔽状态栏下拉

6.0解决办法

源码位置 SystemUI\src\com\android\systemui\statusbar\phone\PhoneStatusBarView.java

@Override
public boolean onTouchEvent(MotionEvent event) {
    boolean barConsumedEvent = mBar.interceptTouchEvent(event);

    if (DEBUG_GESTURES) {
        if (event.getActionMasked() != MotionEvent.ACTION_MOVE) {
            EventLog.writeEvent(EventLogTags.SYSUI_PANELBAR_TOUCH,
                    event.getActionMasked(), (int) event.getX(), (int) event.getY(),
                    barConsumedEvent ? 1 : 0);
        }
    }

    // return barConsumedEvent || super.onTouchEvent(event);
    return false;
}

直接返回false，action_move不会执行，代码看似简单，实则super.onTouchEvent(event)调用的是PanelBar.java中的onTouchEvent()

8.1解决办法（同上）

6.0和8.1的状态栏代码是有差异的，但是通过上面的方法都能达到需求效果

6.0的PhoneStatusBarView调用onTouchEvent()，最终调用PanelBar的onTouchEvent()

8.1的PhoneStatusBarView调用onTouchEvent()，接着调用PanelBar的onTouchEvent()，最终调用PanelView的onTouchEvent()

从根本上阻止事件的传递来达到屏蔽下拉的效果

补充

如果需要动态的控制是否允许下拉状态栏，可以通过广播通知，接受传递的参数，持久化保存(可通过SharedPreference或者Settings.Global.xxxx)当前状态栏的状态，一般建议采用Settings.Global保存。

具体步骤

1. 在frameworks\base\core\java\android\provider\Settings.java中Globel内部类下添加变量名称，比如OPEN_PANEL_ENABLED
2. 通过make update-api指令重新编译，因为在Settings中修改后需要编译才能对应到这两文件frameworks/base/api/system-current.txt、frameworks/base/api/current.txt
3. 在广播接收的地方通过Settings.Global.putInt(context.getContentResolver(), Settings.Global.OPEN_PANEL_ENABLED, 1) 保存值
   （ps 可通过adb命令 adb shell settings put global open_panel_enabled 1 模拟写入 adb shell settings get global open_panel_enabled 模拟查看）
4. 将刚刚的return false改成

boolean flag=Settings.Global.getInt(getContext().getContentResolver(), Settings.Global.OPEN_PANEL_ENABLED,1)==1;
return flag ? barConsumedEvent || super.onTouchEvent(event) : flag;

屏蔽导航栏显示

6.0解决办法

源码位置SystemUI\src\com\android\systemui\statusbar\phone\PhoneStatusBar.java

@Override
public void start() {
    mDisplay = ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE))
            .getDefaultDisplay();
    updateDisplaySize();
    mScrimSrcModeEnabled = mContext.getResources().getBoolean(
            R.bool.config_status_bar_scrim_behind_use_src);

    super.start(); // calls createAndAddWindows()
    mMediaSessionManager
            = (MediaSessionManager) mContext.getSystemService(Context.MEDIA_SESSION_SERVICE);
    // TODO: use MediaSessionManager.SessionListener to hook us up to future updates
    // in session state

     addNavigationBar();

     .....
}

直接注释addNavigationBar()就能达到需求效果

8.1解决办法

源码位置SystemUI\src\com\android\systemui\statusbar\phone\StatusBar.java

protected void makeStatusBarView() {
    final Context context = mContext;
    updateDisplaySize(); // populates mDisplayMetrics
    updateResources();
    updateTheme();

    ....

    try {
        boolean showNav = mWindowManagerService.hasNavigationBar();
        if (DEBUG) Log.v(TAG, "hasNavigationBar=" + showNav);
        if (showNav) {
            createNavigationBar();
        }
    } catch (RemoteException ex) {
        // no window manager? good luck with that
    }

    ....
}

直接注释createNavigationBar()或者将showNav=false就能达到需求效果

代码流程分析

6.0和8.1的导航栏都是通过WindowManager的addView来添加的，通过WindowManager的removeViewImmediate来移除

1、6.0的addNavigationBar实现，通过addView将mNavigationBarView添加，prepareNavigationBarView方法设置了点击、触摸、长按事件，无需关心

private void addNavigationBar() {
    if (DEBUG) Log.v(TAG, "addNavigationBar: about to add " + mNavigationBarView);
    if (mNavigationBarView == null) return;

    prepareNavigationBarView();

    mWindowManager.addView(mNavigationBarView, getNavigationBarLayoutParams());
    mNavigationShown=true;
}

查找到在makeStatusBarView()中，mNavigationBarView初始化,加载navigation_bar布局文件

 protected PhoneStatusBarView makeStatusBarView() {
    final Context context = mContext;

    Resources res = context.getResources();

    updateDisplaySize(); // populates mDisplayMetrics
    updateResources();
    ...
    mNavigationBarView = (NavigationBarView) View.inflate(context, R.layout.navigation_bar, null);

    mNavigationBarView.setDisabledFlags(mDisabled1);
    mNavigationBarView.setBar(this);
    mNavigationBarView.setOnVerticalChangedListener(
            new NavigationBarView.OnVerticalChangedListener() {
        @Override
        public void onVerticalChanged(boolean isVertical) {
            if (mAssistManager != null) {
                mAssistManager.onConfigurationChanged();
            }
            mNotificationPanel.setQsScrimEnabled(!isVertical);
        }
    });
    mNavigationBarView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            checkUserAutohide(v, event);
            return false;
        }});
}

2、8.1的createNavigationBar实现，发现是通过NavigationBarFragment来实例化mNavigationBarView

protected void createNavigationBar() {
    mNavigationBarView = NavigationBarFragment.create(mContext, (tag, fragment) -> {
        mNavigationBar = (NavigationBarFragment) fragment;
        if (mLightBarController != null) {
            mNavigationBar.setLightBarController(mLightBarController);
        }
        mNavigationBar.setCurrentSysuiVisibility(mSystemUiVisibility);
    });
}

NavigationBarFragment的crate方法通过addView将mNavigationBarView添加，加载navigation_bar_window布局

public static View create(Context context, FragmentListener listener) {
    WindowManager.LayoutParams lp = new WindowManager.LayoutParams(
            LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT,
            WindowManager.LayoutParams.TYPE_NAVIGATION_BAR,
            WindowManager.LayoutParams.FLAG_TOUCHABLE_WHEN_WAKING
                    | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                    | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                    | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
                    | WindowManager.LayoutParams.FLAG_SPLIT_TOUCH
                    | WindowManager.LayoutParams.FLAG_SLIPPERY,
            PixelFormat.TRANSLUCENT);
    lp.token = new Binder();
    lp.setTitle("NavigationBar");
    lp.windowAnimations = 0;

    View navigationBarView = LayoutInflater.from(context).inflate(
            R.layout.navigation_bar_window, null);

    if (DEBUG) Log.v(TAG, "addNavigationBar: about to add " + navigationBarView);
    if (navigationBarView == null) return null;

    context.getSystemService(WindowManager.class).addView(navigationBarView, lp);
    FragmentHostManager fragmentHost = FragmentHostManager.get(navigationBarView);
    NavigationBarFragment fragment = new NavigationBarFragment();
    fragmentHost.getFragmentManager().beginTransaction()
            .replace(R.id.navigation_bar_frame, fragment, TAG)
            .commit();
    fragmentHost.addTagListener(TAG, listener);
    return navigationBarView;
}

补充

依旧是通过广播来动态控制导航栏的显示和隐藏

6.0已在开头文章中写过，这里就只补充8.1的显示和隐藏

源码位置SystemUI\src\com\android\systemui\statusbar\phone\StatusBar.java

private static final String SHOW_NAVIGATION = "cc.intent.systemui.shownavigation";
private static final String HIDE_NAVIGATION = "cc.intent.systemui.hidenavigation";

 private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        Log.e(TAG, "onReceive: " + intent);
        String action = intent.getAction();
        if (HIDE_NAVIGATION.equals(action)) {
            if (mNavigationBarView == null) return;

            mWindowManager.removeViewImmediate(mNavigationBarView);
            mNavigationBarView = null;
        }else if (SHOW_NAVIGATION.equals(action)) {
            if (mNavigationBarView != null) return;

            createNavigationBar();
        }
    }
};