Android Studio 3.1,Java 1.8
我尝试使用数据绑定:
在这里 settings.xml 布局:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<variable
name="handler"
type="com.myproject.SettingsFragment" />
</data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.constraint.ConstraintLayout
android:id="@+id/contentContainer"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.constraint.ConstraintLayout
android:id="@+id/contactUsContainer"
android:layout_width="match_parent"
android:layout_height="50dp"
android:onClick="@{handler::onClickContactUs}">
<ImageView
android:id="@+id/contactUsImageView"
android:layout_width="28dp"
android:layout_height="28dp"
app:srcCompat="@drawable/ic_settings_contacts_us"
<TextView
android:id="@+id/contactUsTextView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="@string/contact_us"/>
</android.support.constraint.ConstraintLayout>
</android.support.constraint.ConstraintLayout>
</FrameLayout>
</ScrollView>
</android.support.constraint.ConstraintLayout>
</layout>
在这里fragment settingsfragment.java :
public class SettingsFragment extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
SettingsBinding binding = DataBindingUtil.setContentView(getActivity(), R.layout.settings);
binding.setHandler(this);
return binding.getRoot();
}
public void onClickContactUs(View view) {
}
}
但是我会出错:
FATAL EXCEPTION: main
java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
at android.view.ViewGroup.addViewInner(ViewGroup.java:3337)
at android.view.ViewGroup.addView(ViewGroup.java:3208)
at android.view.ViewGroup.addView(ViewGroup.java:3165)
at android.view.ViewGroup.addView(ViewGroup.java:3145)
android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1425)
android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1740)
android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1809)
android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:799)
android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580)
android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367)
android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322)
android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2229)
databindingutil.setContentView()应用于在活动中绑定,因为该方法将设置活动的内容视图(就像通常使用SetContentView()方法一样)。这就是为什么您会发现视图(binding.getRoot())已经将其附加到父视图的原因。
在您的片段中,使用databindingutil.inflate()夸大布局并创建绑定而无需实际附加视图(片段本身会自行执行):
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
SettingsBinding binding = DataBindingUtil.inflate(inflater, R.layout.settings, container, false);
binding.setHandler(this);
return binding.getRoot();
}