有时我会收到以下错误信息:
在Fragment附加到FragmentManager之前,无法执行onGetLayoutInflater()
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,在第1117行首先调用了方法
getLayoutInflater()
,然后在第1151行调用了另一个方法。第一个方法是这个:
/**
* 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;
}
第二个方法会抛出异常并被标记为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;
}
这里调用了一个被弃用的函数,这正常吗?我认为在调用getLayoutInflater()之前检查isAdded()后不应该抛出异常。
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);
}