android - 在 Fragment 附加到 FragmentManager 之前不能执行 onGetLayoutInflater()

Question

我有时会收到以下消息的异常:

onGetLayoutInflater() cannot be executed until the Fragment is attached to the FragmentManager

我的完整堆栈跟踪(使用 CompositeAndroid 作为父 fragment ):

Fatal Exception: java.lang.IllegalStateException: onGetLayoutInflater() cannot be executed until the Fragment is attached to the FragmentManager.
       at android.support.v4.app.Fragment.getLayoutInflater(Fragment.java:1151)
       at com.pascalwelsch.compositeandroid.fragment.CompositeFragment.super_getLayoutInflater(CompositeFragment.java:1310)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$7.call(FragmentDelegate.java:204)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$7.call(FragmentDelegate.java:197)
       at com.pascalwelsch.compositeandroid.fragment.FragmentPlugin.getLayoutInflater(FragmentPlugin.java:149)
       at com.pascalwelsch.compositeandroid.fragment.FragmentPlugin.getLayoutInflater(FragmentPlugin.java:1269)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$7.call(FragmentDelegate.java:202)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$7.call(FragmentDelegate.java:197)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate.getLayoutInflater(FragmentDelegate.java:208)
       at com.pascalwelsch.compositeandroid.fragment.CompositeFragment.getLayoutInflater(CompositeFragment.java:163)
       at android.support.v4.app.Fragment.onGetLayoutInflater(Fragment.java:1101)
       at com.pascalwelsch.compositeandroid.fragment.CompositeFragment.super_onGetLayoutInflater(CompositeFragment.java:1710)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$32.call(FragmentDelegate.java:769)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$32.call(FragmentDelegate.java:762)
       at com.pascalwelsch.compositeandroid.fragment.FragmentPlugin.onGetLayoutInflater(FragmentPlugin.java:528)
       at com.pascalwelsch.compositeandroid.fragment.FragmentPlugin.onGetLayoutInflater(FragmentPlugin.java:1456)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$32.call(FragmentDelegate.java:767)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate$32.call(FragmentDelegate.java:762)
       at com.pascalwelsch.compositeandroid.fragment.FragmentDelegate.onGetLayoutInflater(FragmentDelegate.java:773)
       at com.pascalwelsch.compositeandroid.fragment.CompositeFragment.onGetLayoutInflater(CompositeFragment.java:538)
       at android.support.v4.app.Fragment.performGetLayoutInflater(Fragment.java:1132)
       at android.support.v4.app.Fragment.getLayoutInflater(Fragment.java:1117)
       at com.my.app.features.event.EventDetailFragment.attachHeader(EventDetailFragment.java:66)
       ...

我们可以在这里看到，我们首先在第 1117 行调用方法 getLayoutInflater()，然后在第 1151 行调用方法。

第一个是这个:

/**
 * Returns the cached LayoutInflater used to inflate Views of this Fragment. If
 * {@link #onGetLayoutInflater(Bundle)} has not been called {@link #onGetLayoutInflater(Bundle)}
 * will be called with a {@code null} argument and that value will be cached.
 * <p>
 * The cached LayoutInflater will be replaced immediately prior to
 * {@link #onCreateView(LayoutInflater, ViewGroup, Bundle)} and cleared immediately after
 * {@link #onDetach()}.
 *
 * @return The LayoutInflater used to inflate Views of this Fragment.
 */
public final LayoutInflater getLayoutInflater() {
    if (mLayoutInflater == null) {
        return performGetLayoutInflater(null);
    }
    return mLayoutInflater;
}

第二个是抛出 Exception 并标记为 deprecated 的那个:

/**
 * Override {@link #onGetLayoutInflater(Bundle)} when you need to change the
 * LayoutInflater or call {@link #getLayoutInflater()} when you want to
 * retrieve the current LayoutInflater.
 *
 * @hide
 * @deprecated Override {@link #onGetLayoutInflater(Bundle)} or call
 * {@link #getLayoutInflater()} instead of this method.
 */
@Deprecated
@NonNull
@RestrictTo(LIBRARY_GROUP)
public LayoutInflater getLayoutInflater(@Nullable Bundle savedFragmentState) {
    if (mHost == null) {
        throw new IllegalStateException("onGetLayoutInflater() cannot be executed until the "
                + "Fragment is attached to the FragmentManager.");
    }
    LayoutInflater result = mHost.onGetLayoutInflater();
    getChildFragmentManager(); // Init if needed; use raw implementation below.
    LayoutInflaterCompat.setFactory2(result, mChildFragmentManager.getLayoutInflaterFactory());
    return result;
}

他们在这里调用已弃用函数是否正常？而且我认为它不应该抛出 Exception 因为我在调用 getLayoutInflater() 之前检查 isAdded():

private void init () {
    if(isAdded()) {
        attachHeader();
        updateHeader();
    }
}

private void attachHeader() {
    headerBinding = DataBindingUtil.inflate(getLayoutInflater(), layout.event_detail_header,
            binding.formsContainer, false);
    binding.formsContainer.addView(headerBinding.getRoot(), 0);
}

Answer 1

对于 future 的读者。就我而言。我在 Api 响应内的 fragment 中使用 getLayoutInflater，当我尝试更改 fragment 时，出现此错误

Fatal Exception: java.lang.IllegalStateException: onGetLayoutInflater() cannot be executed until the Fragment is attached to the FragmentManager.

所以我通过取消 fragment 的 Api 调用 onDestroy 解决了这个问题

 @Override
    public void onDestroy() {
        super.onDestroy();
        disposable.dispose(); //RxJava
    }

可能对其他用户有帮助。