android - 在 Activity 中永久隐藏导航栏

Question

是否可以永久删除 Activity 上的导航栏？我想删除显示在平板电脑屏幕按钮上的按钮栏，而不是操作栏。 Here .

我知道不建议这样做，我没有做出这个决定，但我需要这样做。在我的布局上，还有另一个按钮可以离开 Activity 。我的应用程序的其余部分可以具有并且确实具有导航栏。

我找到了这段代码并对其进行了一些调整。问题是即使我隐藏了导航栏，也会留下一个黑色空间。我猜系统在计算屏幕尺寸时会考虑导航栏？

public static class Content extends ImageView implements View.OnSystemUiVisibilityChangeListener, View.OnClickListener, ActionBar.OnMenuVisibilityListener {
    Activity mActivity;
    TextView mTitleView;
    Button mPlayButton;
    SeekBar mSeekView;
    boolean mAddedMenuListener;
    boolean mMenusOpen;
    boolean mPaused;
    boolean mNavVisible;
    int mLastSystemUiVis;

    Runnable mNavHider = new Runnable() {
        @Override public void run() {
            setNavVisibility(false);
        }
    };

    public Content(Context context, AttributeSet attrs) {
        super(context, attrs);
        setOnSystemUiVisibilityChangeListener(this);
        setOnClickListener(this);
    }

    public void init(Activity activity, TextView title, Button playButton,
            SeekBar seek) {
        // This called by the containing activity to supply the surrounding
        // state of the video player that it will interact with.
        mActivity = activity;
        mTitleView = title;
        mPlayButton = playButton;
        mSeekView = seek;
        mPlayButton.setOnClickListener(this);
        setPlayPaused(true);
    }

    @Override protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        if (mActivity != null) {
            mAddedMenuListener = true;
            mActivity.getActionBar().addOnMenuVisibilityListener(this);
        }
    }

    @Override protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        if (mAddedMenuListener) {
            mActivity.getActionBar().removeOnMenuVisibilityListener(this);
        }
    }

    @Override public void onSystemUiVisibilityChange(int visibility) {
        // Detect when we go out of nav-hidden mode, to clear our state
        // back to having the full UI chrome up.  Only do this when
        // the state is changing and nav is no longer hidden.
        int diff = mLastSystemUiVis ^ visibility;
        mLastSystemUiVis = visibility;
        if ((diff&SYSTEM_UI_FLAG_HIDE_NAVIGATION) != 0
                && (visibility&SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0) {
            setNavVisibility(true);
        }
    }

    @Override protected void onWindowVisibilityChanged(int visibility) {
        super.onWindowVisibilityChanged(visibility);

        // When we become visible or invisible, play is paused.
        setPlayPaused(true);
    }

    @Override public void onClick(View v) {
        if (v == mPlayButton) {
            // Clicking on the play/pause button toggles its state.
            setPlayPaused(!mPaused);
        } else {
            // Clicking elsewhere makes the navigation visible.
            setNavVisibility(true);
        }
    }

    @Override public void onMenuVisibilityChanged(boolean isVisible) {
        mMenusOpen = isVisible;
        setNavVisibility(true);
    }

    void setPlayPaused(boolean paused) {
        mPaused = paused;
        mPlayButton.setText(paused ? R.string.play : R.string.pause);
        setKeepScreenOn(!paused);
        setNavVisibility(true);
    }

    void setNavVisibility(boolean visible) {
        int newVis = SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                | SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                | SYSTEM_UI_FLAG_LAYOUT_STABLE;
        if (!visible) {
            newVis |= SYSTEM_UI_FLAG_LOW_PROFILE | SYSTEM_UI_FLAG_FULLSCREEN
                    | SYSTEM_UI_FLAG_HIDE_NAVIGATION;
        }

        // If we are now visible, schedule a timer for us to go invisible.
        if (visible) {
            Handler h = getHandler();
            if (h != null) {
                h.removeCallbacks(mNavHider);
                if (!mMenusOpen && !mPaused) {
                    // If the menus are open or play is paused, we will not auto-hide.
                    h.postDelayed(mNavHider, 1500);
                }
            }
        }

        // Set the new desired visibility.
        setSystemUiVisibility(newVis);
        mTitleView.setVisibility(visible ? VISIBLE : INVISIBLE);
        mPlayButton.setVisibility(visible ? VISIBLE : INVISIBLE);
        mSeekView.setVisibility(visible ? VISIBLE : INVISIBLE);
    }

}

Answer 1

有一个从 KitKat (4.4.2) 开始的解决方案，称为沉浸式模式:https://developer.android.com/training/system-ui/immersive.html

基本上，您应该将此代码添加到您的 onResume() 方法中:

View decorView = getWindow().getDecorView();
decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                              | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                              | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                              | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                              | View.SYSTEM_UI_FLAG_FULLSCREEN
                              | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);