在 Fragment 附加到 FragmentManager 之前，无法执行 onGetLayoutInflater()

Question

我有时会收到带有以下消息的异常：

onGetLayoutInflater() 直到 Fragment 被执行 附加到 FragmentManager

我的完整堆栈跟踪（使用 CompositeAndroid 作为父片段）：

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)
       ...

我们可以看到，我们首先在第 1117 行调用了方法 getLayoutInflater()，然后在第 1151 行调用了方法。

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：

/**
 * 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deprecated 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()之前正在检查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

对于未来的读者。就我而言。我在 Api 响应中的 Fragment 中使用getLayoutInflater，当我尝试更改片段时，我收到了这个错误

致命异常：java.lang.IllegalStateException： onGetLayoutInflater() 直到 Fragment 被执行 附加到 FragmentManager。

所以我通过取消我的 Api 调用 onDestroy of fragment 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。

Answer 2

在 mHost.onGetLayoutInflater() 使用它检查 Fragment 是否附加之前，您必须首先确保 Fragment 已附加到 FragmentManager：

    Activity activity = getActivity();
    if (isAdded() && activity != null){ // Check the fragment status
        LayoutInflater result = mHost.onGetLayoutInflater();
        getChildFragmentManager(); // Init if needed; use raw implementation below.
        LayoutInflaterCompat.setFactory2(result, 
        mChildFragmentManager.getLayoutInflaterFactory());
    }else{
        LayoutInflater result = null;
    }

Answer 3

我觉得这仍然可以帮助某人。 在绑定视图时使用 onCreateView 中的 inflater 似乎可以解决此错误 - 致命异常：java.lang.IllegalStateException: onGetLayoutInflater() 在 Fragment 附加到 FragmentManager 之前无法执行。

@Override
            public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            render(inflater);
        }
    
    private void render(LayoutInflater inflater) {
    GenericViewBinding genericViewBinding =  GenericViewBinding .inflate(inflater);
    }

在我的情况下，这个错误发生在内部（使用默认打开离线缓存的 Google Firestore，这使得响应感觉即时）documentReference.addSnapshotListener(new EventListener() { } 当我尝试当我的片段尚未附加到 FragmentManager 时，膨胀视图。

我写的很谦虚，请不要害羞。我只是想帮忙。或许还有什么我还是不明白的。我仍然很想收到你的来信。谢谢。

Answer 4

使用以下代码检查 Fragment 是否在使用前被销毁：

科特林：

if (activity?.isFinishing == true ||
     activity?.isChangingConfigurations == true || this.isRemoving ||
     this.activity == null || this.isDetached || !this.isAdded || this.view== null) {
                                return
                            }else{Todo()}