Question

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，我有一个与Butterknife的片段：

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。

我尝试添加'@Nullable'和'@Optional'注释，但它不起作用

Answer 1

只需从include标记中删除id即可，即使对于包含的布局中的字段，绑定仍然有效。

Answer 2

MainActivity，

public MainActivity extends AppCompatActivity {
    // 1. First, we declare the layout that was included as a View objects.
    @BindView( R.id.layout_1 ) View layout_1;
    @BindView( R.id.layout_2 ) View layout_2;

    @Override
    protected void onCreate( Bundle savedInstanceState ) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.activity_main );

        // 2. In here, we bind the included layouts
        ButterKnife.bind( this );

        // 4. Then, we create objects of the type of the IncludedLayout.
        //      In this example the layout reuse the same layout twice, so, there are two
        //      IncludedLayouts.
        IncludedLayout includedLayout_1 = new IncludedLayout();
        IncludedLayout includedLayout_2 = new IncludedLayout();

        // 5. We bind the elements of the included layouts.
        ButterKnife.bind( includedLayout_1, layout_1 );
        ButterKnife.bind( includedLayout_2, layout_2 );

        // 6. And, finally, we use them.
        includedLayout_1.displayed_text.setText(  "Hello" );
        includedLayout_2.displayed_text.setText(  "Hey!" );
    }

    // 3. We create a static class that will be an container of the elements
    //     of the included layout. In here we declare the components that
    //     hold this. In this example, there is only one TextView.
    static class IncludedLayout {
        @BindView( R.id.displayed_text ) TextView displayed_text;
    }
}

MainActivity的XML：

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <include android:id="@+id/layout_1" layout="@layout/included_layout" />
        <include android:id="@+id/layout_2" layout="@layout/included_layout" />
</LinearLayout>

包含布局的XML：

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/displayed_text"/>
</LinearLayout>

就是这样！

信用：Reference

Answer 3

请访问Butterknife issue

作者@JakeWharton说 -

Put an ID on the <include> and bind it to an arbitrary View field for each one. 
Then create an object which binds the inner views

static class Something {
  @Bind(R.id.something) TextView somethingView;
}

You can then create multiple instances of that object
and call ButterKnife.bind(something1, include1) and 
ButterKnife.bind(something2, include2) and so on.

Consider also just making a custom view instead of using <include> which has 
proper APIs to get its children (or at least binds them to fields itself).

Answer 4

我建议您使用Google提供的Data Binding Library代替Butterknife

Answer 5

由于这个问题已经很久了。

如今（2019年10月），我可以在include标签中连接我的ID。

在深入研究之前，尝试做类似原始问题的事情。

@BindView(R.id.your_button_id_inside_include_tag) Button button;

Butterknife不适用于Include标签

5 个答案: