子约束布局不水平扩展的约束布局
Constraint layout with child constraint layouts not expanding horizontally
我正在尝试构建一个矩形视图（跨越屏幕的宽度），它被水平分成三个块，并且我正在使用约束布局这样做。左侧和右侧块具有指定的宽度，但中心块应扩展以适应剩余的 space。因为我要求最左边的块具有与父块不同的背景颜色，所以我将其子块分组到另一个约束布局中。我给出了下面的布局XML：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="100dp"
android:layout_marginTop="8dp"
android:background="#10000000"
xmlns:tools="http://schemas.android.com/tools">
<android.support.constraint.ConstraintLayout
android:id="@+id/abc"
android:layout_width="100dp"
android:layout_height="match_parent"
android:background="#50000000"
android:layout_marginEnd="8dp"
android:padding="2dp"
app:layout_constraintHorizontal_chainStyle="spread_inside"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/jkl"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:id="@+id/def"
android:gravity="start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/ghi"
android:gravity="start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="14sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/def" />
</android.support.constraint.ConstraintLayout>
<!-- This should expand to fit the remainder of the screen width -->
<android.support.constraint.ConstraintLayout
android:id="@+id/jkl"
android:layout_width="0dp"
android:layout_height="match_parent"
app:layout_constraintHorizontal_chainStyle="spread_inside"
app:layout_constraintEnd_toStartOf="@+id/stu"
app:layout_constraintStart_toEndOf="@+id/abc">
<TextView
android:id="@+id/mno"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="top|start"
android:textColor="#a0000000"
android:textSize="14sp"
android:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/pqr"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="top|start"
android:textColor="#a0000000"
android:textSize="14sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/mno" />
</android.support.constraint.ConstraintLayout>
<ImageButton
android:id="@+id/stu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:src="@drawable/x"
app:layout_constraintHorizontal_chainStyle="spread_inside"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/jkl"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
不幸的是，中间块没有展开以适应屏幕的剩余宽度。有谁知道如何实现这一目标？我在这里做错了什么吗？
编辑：
根据 Ben P. 的回复，上面的 XML 可能没问题，但包含此布局的布局有问题。因此，我在下面提供了它们。
此布局 XML 是上面 XML 的父布局：
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/parent_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.Parent">
</android.support.v7.widget.RecyclerView>
此布局 XML 是上面 RecyclerView XML 的父级：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.MainActivity">
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<include layout="@layout/bottom_navigation" />
</android.support.constraint.ConstraintLayout>
编辑 2：
根据要求，我提供了完整的代码库：
MainActivity.java:
public class MainActivity extends AppCompatActivity {
private FragmentManager mFragmentManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mFragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, new Foo());
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
}
Foo.java:
public class Foo extends Fragment {
private String[] mDataset;
private OnFragmentInteractionListener mListener;
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
public Foo() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment Foo.
*/
// TODO: Rename and change types and number of parameters
public static Foo newInstance(String param1, String param2) {
Foo fragment = new Foo();
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
initDataset();
}
private void initDataset() {
mDataset = new String[1];
mDataset[0] = "Hello World";
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_foo, container, false);
mRecyclerView = view.findViewById(R.id.foo_view);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new FooAdapter(mDataset);
mRecyclerView.setAdapter(mAdapter);
return view;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
FooAdapter.java:
public class FooAdapter extends RecyclerView.Adapter<FooAdapter.ViewHolder> {
private String[] mDataset;
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView mFoofoo;
private TextView mBarbar;
public ViewHolder(View itemView) {
super(itemView);
mFoofoo = itemView.findViewById(R.id.foofoo);
mBarbar = itemView.findViewById(R.id.barbar);
}
public TextView getFoofoo() {
return mFoo;
}
public TextView getBarbar() {
return mBar;
}
}
public FooAdapter(String[] mDataset) {
this.mDataset = mDataset;
}
@Override
public FooAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.bar, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(FooAdapter.ViewHolder holder, int position) {
String text = mDataset[position];
holder.getBarbar().setText(text);
holder.getFoofoo().setText(text);
}
@Override
public int getItemCount() {
return mDataset.length;
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.MainActivity">
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#eaff73"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
fragment.xml:
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/foo_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#8df78b"
tools:context="com.example.Foo">
</android.support.v7.widget.RecyclerView>
bar.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="104dp"
android:layout_marginTop="4dp"
android:background="#10000000"
xmlns:tools="http://schemas.android.com/tools">
<ImageView
android:id="@+id/backg"
android:background="#50000000"
android:layout_width="104dp"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/foofoo"
android:gravity="start"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageButton
android:id="@+id/action"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:layout_width="wrap_content"
android:src="@drawable/pic"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/barbar"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/barbar"
android:autoSizeMaxTextSize="24sp"
android:autoSizeMinTextSize="14dp"
android:autoSizeStepGranularity="2dp"
android:autoSizeTextType="uniform"
android:background="#ef0505"
android:gravity="top|start"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:paddingStart="8dp"
android:textColor="#a0000000"
android:textSize="24sp"
android:textStyle="bold"
app:layout_constraintEnd_toStartOf="@id/action"
app:layout_constraintStart_toEndOf="@id/backg"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
非常感谢任何帮助！
更新
这是一套公寓 ConstraintLayout，我相信您会想要它：
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="100dp">
<ImageView
android:id="@+id/image"
android:layout_width="100dp"
android:layout_height="0dp"
android:background="#33000000"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
<TextView
android:id="@+id/text1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="@+id/image"
app:layout_constraintRight_toRightOf="@+id/image"
tools:text="line 1"/>
<TextView
android:id="@+id/text2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toBottomOf="@+id/text1"
app:layout_constraintLeft_toLeftOf="@+id/image"
app:layout_constraintRight_toRightOf="@+id/image"
tools:text="line 2"/>
<TextView
android:id="@+id/text3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toRightOf="@+id/image"
app:layout_constraintRight_toLeftOf="@+id/button"
tools:text="line 3"/>
<TextView
android:id="@+id/text4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toBottomOf="@+id/text3"
app:layout_constraintLeft_toRightOf="@+id/image"
app:layout_constraintRight_toLeftOf="@+id/button"
tools:text="line 4"/>
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
tools:text="button"/>
</android.support.constraint.ConstraintLayout>
它的样子：
原创
这并没有严格回答问题（因为据我所知，发布的布局没有问题），但是...
我认为没有理由使用 ConstraintLayout 来实现此 UI。 ConstraintLayout 的好处是它允许您避免在顶级 View 中嵌套 ViewGroup。但是当你写 ConstraintLayout 时，你仍然将你的 TextView 分组在中级 View.
中
如果您不利用 ConstraintLayout 的无嵌套组织能力，我认为使用更简单的顶层视图是更好的主意。这是用 LinearLayouts 重新实现的 UI：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="8dp"
android:background="#10000000"
android:orientation="horizontal">
<LinearLayout
android:id="@+id/abc"
android:layout_width="100dp"
android:layout_height="match_parent"
android:padding="2dp"
android:background="#50000000"
android:orientation="vertical">
<TextView
android:id="@+id/def"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="18sp"
tools:text="line 1"/>
<TextView
android:id="@+id/ghi"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="14sp"
tools:text="line 2"/>
</LinearLayout>
<LinearLayout
android:id="@+id/jkl"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/mno"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#a0000000"
android:textSize="14sp"
android:textStyle="bold"
tools:text="line 1"/>
<TextView
android:id="@+id/pqr"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#a0000000"
android:textSize="14sp"
tools:text="line 2"/>
</LinearLayout>
<ImageButton
android:id="@+id/stu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="16dp"
android:layout_marginEnd="16dp"
android:src="@drawable/plus"/>
</LinearLayout>
我不知道为什么会这样，但确实如此。
在 bar.xml 中，将外部 ConstraintLayout 的高度替换为 wrap_content（而不是 104dp）。
同样在 bar.xml 中，将 ImageView 的身高替换为 104dp（而不是 0dp）。
这具有保持布局设计相同的净效果...它只是 ConstraintLayout 的高度由 ImageView 的高度定义，而不是相反.
如果我不得不猜测为什么这会有所不同，我会假设 LinearLayoutManager 测量其子项的方式存在一些怪癖，并且当它看到固定高度时会忽略 match_parent宽度。但这是疯狂的猜测。
我正在尝试构建一个矩形视图（跨越屏幕的宽度），它被水平分成三个块，并且我正在使用约束布局这样做。左侧和右侧块具有指定的宽度，但中心块应扩展以适应剩余的 space。因为我要求最左边的块具有与父块不同的背景颜色，所以我将其子块分组到另一个约束布局中。我给出了下面的布局XML：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="100dp"
android:layout_marginTop="8dp"
android:background="#10000000"
xmlns:tools="http://schemas.android.com/tools">
<android.support.constraint.ConstraintLayout
android:id="@+id/abc"
android:layout_width="100dp"
android:layout_height="match_parent"
android:background="#50000000"
android:layout_marginEnd="8dp"
android:padding="2dp"
app:layout_constraintHorizontal_chainStyle="spread_inside"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/jkl"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:id="@+id/def"
android:gravity="start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/ghi"
android:gravity="start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="14sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/def" />
</android.support.constraint.ConstraintLayout>
<!-- This should expand to fit the remainder of the screen width -->
<android.support.constraint.ConstraintLayout
android:id="@+id/jkl"
android:layout_width="0dp"
android:layout_height="match_parent"
app:layout_constraintHorizontal_chainStyle="spread_inside"
app:layout_constraintEnd_toStartOf="@+id/stu"
app:layout_constraintStart_toEndOf="@+id/abc">
<TextView
android:id="@+id/mno"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="top|start"
android:textColor="#a0000000"
android:textSize="14sp"
android:textStyle="bold"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/pqr"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="top|start"
android:textColor="#a0000000"
android:textSize="14sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/mno" />
</android.support.constraint.ConstraintLayout>
<ImageButton
android:id="@+id/stu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:src="@drawable/x"
app:layout_constraintHorizontal_chainStyle="spread_inside"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/jkl"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
不幸的是，中间块没有展开以适应屏幕的剩余宽度。有谁知道如何实现这一目标？我在这里做错了什么吗？
编辑：
根据 Ben P. 的回复，上面的 XML 可能没问题，但包含此布局的布局有问题。因此，我在下面提供了它们。
此布局 XML 是上面 XML 的父布局：
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/parent_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.Parent">
</android.support.v7.widget.RecyclerView>
此布局 XML 是上面 RecyclerView XML 的父级：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.MainActivity">
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<include layout="@layout/bottom_navigation" />
</android.support.constraint.ConstraintLayout>
编辑 2：
根据要求，我提供了完整的代码库：
MainActivity.java:
public class MainActivity extends AppCompatActivity {
private FragmentManager mFragmentManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mFragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, new Foo());
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
}
Foo.java:
public class Foo extends Fragment {
private String[] mDataset;
private OnFragmentInteractionListener mListener;
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
public Foo() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment Foo.
*/
// TODO: Rename and change types and number of parameters
public static Foo newInstance(String param1, String param2) {
Foo fragment = new Foo();
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
initDataset();
}
private void initDataset() {
mDataset = new String[1];
mDataset[0] = "Hello World";
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_foo, container, false);
mRecyclerView = view.findViewById(R.id.foo_view);
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new FooAdapter(mDataset);
mRecyclerView.setAdapter(mAdapter);
return view;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
FooAdapter.java:
public class FooAdapter extends RecyclerView.Adapter<FooAdapter.ViewHolder> {
private String[] mDataset;
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView mFoofoo;
private TextView mBarbar;
public ViewHolder(View itemView) {
super(itemView);
mFoofoo = itemView.findViewById(R.id.foofoo);
mBarbar = itemView.findViewById(R.id.barbar);
}
public TextView getFoofoo() {
return mFoo;
}
public TextView getBarbar() {
return mBar;
}
}
public FooAdapter(String[] mDataset) {
this.mDataset = mDataset;
}
@Override
public FooAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.bar, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(FooAdapter.ViewHolder holder, int position) {
String text = mDataset[position];
holder.getBarbar().setText(text);
holder.getFoofoo().setText(text);
}
@Override
public int getItemCount() {
return mDataset.length;
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.MainActivity">
<FrameLayout
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#eaff73"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
fragment.xml:
<android.support.v7.widget.RecyclerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/foo_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#8df78b"
tools:context="com.example.Foo">
</android.support.v7.widget.RecyclerView>
bar.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="104dp"
android:layout_marginTop="4dp"
android:background="#10000000"
xmlns:tools="http://schemas.android.com/tools">
<ImageView
android:id="@+id/backg"
android:background="#50000000"
android:layout_width="104dp"
android:layout_height="match_parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/foofoo"
android:gravity="start"
android:layout_width="100dp"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="18sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageButton
android:id="@+id/action"
android:layout_height="wrap_content"
android:layout_marginEnd="16dp"
android:layout_width="wrap_content"
android:src="@drawable/pic"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/barbar"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/barbar"
android:autoSizeMaxTextSize="24sp"
android:autoSizeMinTextSize="14dp"
android:autoSizeStepGranularity="2dp"
android:autoSizeTextType="uniform"
android:background="#ef0505"
android:gravity="top|start"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:paddingStart="8dp"
android:textColor="#a0000000"
android:textSize="24sp"
android:textStyle="bold"
app:layout_constraintEnd_toStartOf="@id/action"
app:layout_constraintStart_toEndOf="@id/backg"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
非常感谢任何帮助！
更新
这是一套公寓 ConstraintLayout，我相信您会想要它：
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="100dp">
<ImageView
android:id="@+id/image"
android:layout_width="100dp"
android:layout_height="0dp"
android:background="#33000000"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
<TextView
android:id="@+id/text1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="@+id/image"
app:layout_constraintRight_toRightOf="@+id/image"
tools:text="line 1"/>
<TextView
android:id="@+id/text2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toBottomOf="@+id/text1"
app:layout_constraintLeft_toLeftOf="@+id/image"
app:layout_constraintRight_toRightOf="@+id/image"
tools:text="line 2"/>
<TextView
android:id="@+id/text3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toRightOf="@+id/image"
app:layout_constraintRight_toLeftOf="@+id/button"
tools:text="line 3"/>
<TextView
android:id="@+id/text4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:padding="4dp"
app:layout_constraintTop_toBottomOf="@+id/text3"
app:layout_constraintLeft_toRightOf="@+id/image"
app:layout_constraintRight_toLeftOf="@+id/button"
tools:text="line 4"/>
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
tools:text="button"/>
</android.support.constraint.ConstraintLayout>
它的样子：
原创
这并没有严格回答问题（因为据我所知，发布的布局没有问题），但是...
我认为没有理由使用 ConstraintLayout 来实现此 UI。 ConstraintLayout 的好处是它允许您避免在顶级 View 中嵌套 ViewGroup。但是当你写 ConstraintLayout 时，你仍然将你的 TextView 分组在中级 View.
如果您不利用 ConstraintLayout 的无嵌套组织能力，我认为使用更简单的顶层视图是更好的主意。这是用 LinearLayouts 重新实现的 UI：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="100dp"
android:layout_marginTop="8dp"
android:background="#10000000"
android:orientation="horizontal">
<LinearLayout
android:id="@+id/abc"
android:layout_width="100dp"
android:layout_height="match_parent"
android:padding="2dp"
android:background="#50000000"
android:orientation="vertical">
<TextView
android:id="@+id/def"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="18sp"
tools:text="line 1"/>
<TextView
android:id="@+id/ghi"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#ffffffff"
android:textSize="14sp"
tools:text="line 2"/>
</LinearLayout>
<LinearLayout
android:id="@+id/jkl"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:orientation="vertical">
<TextView
android:id="@+id/mno"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#a0000000"
android:textSize="14sp"
android:textStyle="bold"
tools:text="line 1"/>
<TextView
android:id="@+id/pqr"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#a0000000"
android:textSize="14sp"
tools:text="line 2"/>
</LinearLayout>
<ImageButton
android:id="@+id/stu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="16dp"
android:layout_marginEnd="16dp"
android:src="@drawable/plus"/>
</LinearLayout>
我不知道为什么会这样，但确实如此。
在 bar.xml 中，将外部 ConstraintLayout 的高度替换为 wrap_content（而不是 104dp）。
同样在 bar.xml 中，将 ImageView 的身高替换为 104dp（而不是 0dp）。
这具有保持布局设计相同的净效果...它只是 ConstraintLayout 的高度由 ImageView 的高度定义，而不是相反.
如果我不得不猜测为什么这会有所不同，我会假设 LinearLayoutManager 测量其子项的方式存在一些怪癖，并且当它看到固定高度时会忽略 match_parent宽度。但这是疯狂的猜测。