相关疑难解决方法(0)

我有一个CoordinatorLayout,我有我的按钮:

<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="bottom|end">

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_marginBottom="16dp"
        android:layout_marginRight="16dp"
        android:src="@drawable/icon"
        app:fabSize="normal"/>

</android.support.design.widget.CoordinatorLayout>

然后我有Activity xml,其中包含Button:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    ...

        <include
            android:id="@+id/fabHere"
            layout="@layout/fab_here"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>

</LinearLayout>

在这里,我有一个Butterknife片段:

public class MyFragment extends Fragment {
....
@BindView(R.id.fab) FloatingActionButton fab;


    @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            view = inflater.inflate(R.layout.my_fragment, container, false);
            ButterKnife.bind(this, view);

            return view;
    }
...
 }

但是,如果我启动应用程序,则会出现:
java.lang.IllegalStateException:找不到字段为'fabHere'的ID为2131624072的必需视图'fab'.如果此视图是可选的,请添加"@Nullable"(字段)或"@Optional"(方法)注释.

我试图添加'@Nullable'和'@Optional'注释,但它不起作用