我大概知道怎么处理沉浸式状态栏问题了

[JakeWoki]

public class StatusBarUtil {

    public static final int DEFAULT_STATUS_BAR_ALPHA = 112;


    @TargetApi(Build.VERSION_CODES.KITKAT)
    public static boolean setTranslucentStatus(Activity activity, boolean on) {
        Window win = activity.getWindow();
        WindowManager.LayoutParams winParams = win.getAttributes();
        final int bits = WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
        if (on) {
            winParams.flags |= bits;
        } else {
            winParams.flags &= ~bits;
        }
        win.setAttributes(winParams);

        return on;
    }

    /**
     * 为滑动返回界面设置状态栏颜色
     *
     */
    public static void setColorForSwipeBack(Activity activity, @ColorInt int color) {
        setColorForSwipeBack(activity, color, 0);
    }

    /**
     * 为滑动返回界面设置状态栏颜色
     *
     * @param activity       需要设置的activity
     * @param color          状态栏颜色值
     * @param statusBarAlpha 状态栏透明度
     */
    public static void setColorForSwipeBack(Activity activity, @ColorInt int color, int statusBarAlpha) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {

            ViewGroup contentView = ((ViewGroup) activity.findViewById(android.R.id.content));
            if (contentView == null) return;
            View rootView = contentView.getChildAt(0);
            int statusBarHeight = getStatusBarHeight(activity);
            if (rootView != null && rootView instanceof CoordinatorLayout) {
                final CoordinatorLayout coordinatorLayout = (CoordinatorLayout) rootView;
                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
                    coordinatorLayout.setFitsSystemWindows(false);
                    contentView.setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
                    boolean isNeedRequestLayout = contentView.getPaddingTop() < statusBarHeight;
                    if (isNeedRequestLayout) {
                        contentView.setPadding(0, statusBarHeight, 0, 0);
                        coordinatorLayout.post(new Runnable() {
                            @Override
                            public void run() {
                                coordinatorLayout.requestLayout();
                            }
                        });
                    }
                } else {
                    coordinatorLayout.setStatusBarBackgroundColor(calculateStatusColor(color, statusBarAlpha));
                }
            } else {
                contentView.setPadding(0, statusBarHeight, 0, 0);
                contentView.setBackgroundColor(calculateStatusColor(color, statusBarAlpha));
            }
            setTranslucentStatus(activity, true);
        }
    }


    /**
     * 获取状态栏高度
     *
     * @param context context
     * @return 状态栏高度
     */
    private static int getStatusBarHeight(Context context) {
        // 获得状态栏高度
        int resourceId = context.getResources().getIdentifier("status_bar_height", "dimen", "android");
        return context.getResources().getDimensionPixelSize(resourceId);
    }


    /**
     * 计算状态栏颜色
     *
     * @param color color值
     * @param alpha alpha值
     * @return 最终的状态栏颜色
     */
    private static int calculateStatusColor(@ColorInt int color, int alpha) {
        float a = 1 - alpha / 255f;
        int red = color >> 16 & 0xff;
        int green = color >> 8 & 0xff;
        int blue = color & 0xff;
        red = (int) (red * a + 0.5);
        green = (int) (green * a + 0.5);
        blue = (int) (blue * a + 0.5);
        return 0xff << 24 | red << 16 | green << 8 | blue;
    }

}

public class StatusBarView extends View {
    public StatusBarView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public StatusBarView(Context context) {
        super(context);
    }
}

上面的方法改自StatusBarUtil，修改了setTranslucentStatus(activity, true);
根布局如果是CoordinatorLayout，加上android:fitsSystemWindows="true"；如果不是，就不要加android:fitsSystemWindows="true"，并且需要在根布局设置背景background，不然背景色和状态栏一样（style设置的背景失效，上面的方法相当重新覆盖了背景色）。如果布局有EditText，请用CoordinatorLayout，不然顶不上去

[JakeWoki]

如果使用转场动画
mSlideBackLayout.isComingToFinish();
overridePendingTransition(R.anim.anim_none, R.anim.anim_slide_out);
要放在super.onBackPressed();前面，不然滑动一下就放开，按返回键退出后，会有背景色盖在前面那个Activity上

@oubowu 你试下上面的沉浸式状态栏方法，应该没有问题的