android - 使用 setRetainInstance(true) 时更新的 Fragment 视图状态丢失

Question

我正在尝试保存片段状态。我有一个活动和几个片段。操作顺序：添加第一个片段，手动更改视图（使第一个 LinearLayout GONE 和第二个 LinearLayout VISIBLE 可见），分离片段，添加另一个片段，分离它并再次附加第一个片段。

添加/附加/分离效果很好，但 setRetainInstanse(true) 仅保存初始片段状态。

最后，我在我的片段（而不是第二个）上看到了第一个 LinearLayout，所以我尝试用手制作它，但它不起作用：

@Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);


if (savedInstanceState != null) {
            if (savedInstanceState.containsKey(BUNDLE_IS_LOADING)) {
                if (savedInstanceState.getBoolean(BUNDLE_IS_LOADING)) {
                    mBlockContent.setVisibility(View.GONE);
                    mBlockProgress.setVisibility(View.VISIBLE);

                } else {
                    mBlockContent.setVisibility(View.VISIBLE);
                    mBlockProgress.setVisibility(View.GONE);
                }
            }
        }
        }

        setRetainInstance(true);
}

@Override
public void onSaveInstanceState(Bundle b) {
    super.onSaveInstanceState(b);
    b.putBoolean(BUNDLE_IS_LOADING,
            mBlockProgress.getVisibility() == View.VISIBLE);
}

我使用兼容性库 rev。11.

我的解决方案：

    private boolean isProgressing;

private void saveViewsState() {
    isProgressing = mBlockProgress.getVisibility() == View.VISIBLE;
}

private void switchToProgress() {
    mBlockContent.setVisibility(View.GONE);
    mBlockProgress.setVisibility(View.VISIBLE);
}

private void switchToContent() {
    mBlockContent.setVisibility(View.VISIBLE);
    mBlockProgress.setVisibility(View.GONE);
}

@Override
public void onSaveInstanceState(Bundle b) {
    super.onSaveInstanceState(b);
    saveViewsState();
}

@Override
public void onPause() {
    super.onPause();
    saveViewsState();
}

@Override
public void onResume() {
    super.onResume();
    if (isProgressing) {
        switchToProgress();
    } else {
        switchToContent();
    }
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    if (isProgressing) {
        switchToProgress();
    } else {
        switchToContent();
    }
}