配置更改时导航抽屉关闭

Question

在我的片段中，我通过编程将片段添加到导航抽屉中，然后从右侧打开抽屉。注意，我无法直接访问抽屉布局的xml文件，因此需要一个编程解决方案。抽屉从右侧打开并正确关闭，我保留抽屉的打开/关闭状态，并在配置根据该状态更改后打开它。

问题是，在配置更改时，抽屉关闭（我可以看到抽屉动画到关闭状态），即使我根据保存的InstanceState布尔值恢复其打开/关闭状态。我在DrawerLayout.class中的所有CloseDrawer方法中放置了调试器，但它们没有被击中。

更新：我想我看到了问题所在，但我不知道如何在不扩展抽屉布局本身的情况下解决这个问题<代码>抽屉布局#findDrawerWithGravity，在本例中，它在抽屉布局#onRestoreInstanceState中调用，返回null。

@Override
public void onSaveInstanceState(Bundle outState)
{
    super.onSaveInstanceState(outState);
    outState.putBoolean(STATE_DRAWER_OPEN,
        getDrawerLayout() == null ? false : getDrawerLayout().isDrawerOpen(Gravity.RIGHT));
}

@Override
public void onActivityCreated(Bundle savedInstanceState)
{
    super.onActivityCreated(savedInstanceState);
    if (savedInstanceState != null)
        isDrawerOpen = savedInstanceState.getBoolean(STATE_DRAWER_OPEN);
}

private void setDrawer() //this is called in onCreate
{
    DrawerLayout drawer = getActivity().findViewById(R.id.drawer_layout);
    if (drawer == null)
        drawer = getDrawerLayout();

    View existing = drawer.findViewById(R.id.m_drawer_container);
    if (existing != null)
        drawer.removeView(existing);

    drawer.setFocusableInTouchMode(false);
    drawer.addDrawerListener(this);

    FrameLayout fragmentContainer = new FrameLayout(getActivity());
    fragmentContainer.setId(R.id.m_drawer_container);
    final DrawerLayout.LayoutParams layoutParams = new DrawerLayout.LayoutParams(
        getResources().getDimensionPixelSize(R.dimen.m_drawer_max_width),
        ViewGroup.LayoutParams.MATCH_PARENT, Gravity.RIGHT);
    drawer.addView(fragmentContainer, layoutParams);

    FragmentManager fragmentManager = getFragmentManager();
    MyDrawerFragment mDrawerFragment = null;
    Fragment frag = fragmentManager.findFragmentByTag(TAG_DRAWER_FRAGMENT);
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    if (frag != null && frag.isAdded())
        fragmentTransaction.remove(frag);
    mDrawerFragment = MyDrawerFragment.newInstance(myArgs);
    fragmentTransaction.add(R.id.m_drawer_container, drawerFragment, TAG_DRAWER_FRAGMENT);
    fragmentTransaction.commitAllowingStateLoss();

    if (isDrawerOpen)
        drawer.openDrawer(Gravity.RIGHT);
}

Answer 1

结果，答案是调用drawer.open抽屉（重力。右，假）；来禁用从配置更改恢复的动画。原因是调用drawer.open抽屉（重力。右）默认情况下动画设置为true，深入该方法最终会导致DrawerLayout.java中的此代码块，这会导致不正确的宽度计算，导致抽屉被“隐藏”：

抽屉布局。Java语言

else if (animate) {
    lp.openState |= LayoutParams.FLAG_IS_OPENING;

    if (checkDrawerViewAbsoluteGravity(drawerView, Gravity.LEFT)) {
        mLeftDragger.smoothSlideViewTo(drawerView, 0, drawerView.getTop());
    } else {
        mRightDragger.smoothSlideViewTo(drawerView, getWidth() - drawerView.getWidth(),
                drawerView.getTop());
    }

解决方案是在从配置更改恢复时将animate设置为false。

if (isDrawerOpen && isRestoreFromConfigChange)
    drawer.openDrawer(Gravity.RIGHT, false);