Question

我无法使RecyclerView显示数据，甚至无法对其进行硬编码。我已经尝试了所有发现的内容，以便通过Internet进行这项工作。我的代码有什么问题？

SeleccionarClienteActivity.java

public class SeleccionarClienteActivity extends AppCompatActivity {
    ClientesAdapter adapter;
    String user;

    @Override protected void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_seleccionar_cliente);
        user = getIntent().getStringExtra("user");
        List<Cliente> list = new ArrayList<>();
        list.add(new Cliente("hola", "chau", 1, 1));
        adapter = new ClientesAdapter(list);
        setupUI();
    }

    void setupUI(){
        findViewById(R.id.seleccionarClienteProgressBar).setVisibility(View.GONE);
        setSupportActionBar((Toolbar) findViewById(R.id.seleccionarClienteToolbar));
        Objects.requireNonNull(getSupportActionBar()).setDisplayHomeAsUpEnabled(true);
        if(adapter.getItemCount() <= 0){
            findViewById(R.id.txtSeleccionarClienteEmpty).setVisibility(View.VISIBLE);
        }
        ((RecyclerView) findViewById(R.id.seleccionarClienteRecyclerView)).setAdapter(adapter);
        ((RecyclerView) findViewById(R.id.seleccionarClienteRecyclerView)).addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {
            @Override public boolean onInterceptTouchEvent(@NonNull RecyclerView recyclerView, @NonNull MotionEvent motionEvent){
                View childView = recyclerView.findChildViewUnder(motionEvent.getX(), motionEvent.getY());
                if (childView == null) return false;
                Cliente c = ((ClientesAdapter) recyclerView.getAdapter()).getItemAt(recyclerView.getChildAdapterPosition(childView));
                clientSelected(c);
                return true;
            }

            @Override public void onTouchEvent(@NonNull RecyclerView recyclerView, @NonNull MotionEvent motionEvent){}

            @Override public void onRequestDisallowInterceptTouchEvent(boolean b){}
        });
    }

    void clientSelected(Cliente c){
        Intent i = new Intent(this, SeleccionarArticuloActivity.class);
        i.putExtra("pedido", new Pedido(c));
        startActivity(i);
    }

    private class ClientesAdapter extends RecyclerView.Adapter<ClientesAdapter.ClienteHolder>{
        List<Cliente> list;
        ClientesAdapter(List<Cliente> list){
            this.list = list;
        }

        @NonNull @Override public ClienteHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i){
            return new ClienteHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_cliente, viewGroup, false));
        }

        @Override public void onBindViewHolder(@NonNull ClienteHolder clienteHolder, int i){
            clienteHolder.setClient(list.get(i));
        }

        @Override public int getItemCount(){
            return list.size();
        }

        Cliente getItemAt(int index){
            return list.get(index);
        }

        class ClienteHolder extends RecyclerView.ViewHolder {
            ClienteHolder(@NonNull View itemView){
                super(itemView);
            }

            void setClient(Cliente c){
                ((TextView) itemView.findViewById(R.id.txtNombreCliente)).setText(c.getNombre());
                ((TextView) itemView.findViewById(R.id.txtCodigoCliente)).setText(c.getCodigo());
            }
        }
    }
}

activity_seleccionar_cliente.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".SeleccionarClienteActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/seleccionarClienteRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="visible"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_margin="8dp"
        android:textAlignment="center"
        android:visibility="gone"
        android:id="@+id/txtSeleccionarClienteEmpty"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        android:text="@string/noclients"
        android:textSize="14sp"/>

    <ProgressBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/seleccionarClienteProgressBar"
        android:layout_gravity="center"/>

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.v7.widget.Toolbar
            android:id="@+id/seleccionarClienteToolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@color/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways|snap"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"/>

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

card_cliente.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="72dp"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:clickable="true"
    android:focusable="true"
    android:foreground="?android:attr/selectableItemBackground">

    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/background_light">

        <TextView
            android:id="@+id/txtNombreCliente"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="16dp"
            android:text="Marcelito Perez"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@id/txtCodigoCliente"
            app:layout_constraintHorizontal_bias="0.0"
            app:layout_constraintHorizontal_chainStyle="spread_inside"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/txtCodigoCliente"
            android:text="1296"
            android:layout_margin="16dp"
            app:layout_constraintHorizontal_bias="1.0"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toEndOf="@id/txtNombreCliente"
            app:layout_constraintTop_toTopOf="parent"/>

    </android.support.constraint.ConstraintLayout>
</android.support.v7.widget.CardView>

我检查了所有内容：布局大小，适配器，数据（现在已经进行了硬编码），我什么都没发现。

Answer 1

您没有布局管理器

LinearLayoutManager layoutManager = new LinearLayoutManager(mContext);
myRecycler.setLayoutManager(layoutManager);

您还将多次设置回收站的属性，因此只需定义一次即可，而不是对同一元素多次使用findByID进行投射。

RecyclerView无法显示数据，并且无法在任何地方找到解决方案

1 个答案: