recyclerview

Question

我想创建一个显示列表的应用程序（RecyclerView）。我想在此RecyclerView的Viewholder中包含一个TextView。

MainActivity代码：

    public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private CustomAdapter customAdapter;
    ListView listView;
    public Cursor cursor;
    public StudentRepo studentRepo;
    private final static String TAG = MainActivity.class.getName().toString();

    private static final String TAG_BOOKMARKS="bookmarks";
    private static final String TAG_ABOUT_US="about";

    //recyclerView implementation
    private List<TopSample> wordlist=new ArrayList<>();
    private RecyclerView recyclerView;
    private StudentAdapter studentAdapter;
    //recyclerView implementation done

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        studentRepo = new StudentRepo(this);

        //recyclerView implement
        recyclerView=(RecyclerView)findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);

        DatabaseAccess databaseAccess = DatabaseAccess.getInstance(this);
        databaseAccess.open();
        Cursor cursor= databaseAccess.getInfo();
        cursor.moveToFirst();
        do{
            TopSample topSample=new TopSample(cursor.getString(0));
            wordlist.add(topSample);
        }while (cursor.moveToNext());
        databaseAccess.close();

        studentAdapter=new StudentAdapter(wordlist);
        RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
        recyclerView.setLayoutManager(mLayoutManager);
        //recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.VERTICAL));
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(studentAdapter);

StudentAdapter类

public class StudentAdapter extends RecyclerView.Adapter<StudentAdapter.MyViewHolder> {

    private List<TopSample> wordslist= Collections.emptyList();
    public class MyViewHolder extends RecyclerView.ViewHolder{
        public TextView sword;
        public MyViewHolder(View view){
            super(view);
            sword=(TextView)view.findViewById(R.id.vocab);
        }
    }

    public StudentAdapter(List<TopSample> wordslist){
        this.wordslist=wordslist;
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView=LayoutInflater.from(parent.getContext()).inflate(R.layout.dictionary_list_row,parent,false);
        MyViewHolder vh=new MyViewHolder(itemView);
        return vh;

        //return new MyViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
        TopSample sample=wordslist.get(position);
        holder.sword.setText(sample.getVocab());
    }

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

TopSample代码：

public class TopSample {

    public String vocab;

    public TopSample(){}

    public TopSample(String vocab){
        this.vocab=vocab;
    }

    public String getVocab() {
        return vocab;
    }

    public void setVocab(String vocab) {
        this.vocab = vocab;
    }
}

content_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main"
    tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scrollbars="vertical" />

</RelativeLayout>

dictionary_list_row.xml

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:focusable="true"
                android:clickable="true"
                android:background="?android:attr/selectableItemBackground"
                android:orientation="vertical">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:id="@+id/vocab"
        android:textSize="32dp"
        android:textStyle="bold"/>

</RelativeLayout>

所以输出就像：

正如您所看到的那样，单个视图持有者按预期使用更长的矩形大小，并且回收器视图未采用完整的match_parent命令。

我希望有一个这样的输出，就像一个例子。：

我尝试在两个xml文件中使用不同的组合更改长度和宽度，但没有按预期获得结果。请看看，告诉我我错在哪里。

还有一件事要补充，我从外部数据库中提取数据，其中我很成功，但我认为这个问题可能是布局问题。请指正。

Answer 1

问题是你给了TextView固定的高度和match_parent宽度，并指定了非常大的字体大小..即32dp。

使用以下代码。您可以删除android:textSize="18sp"作为默认尺寸。

 <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"  
    android:id="@+id/vocab"
    android:textSize="18sp"
    android:textStyle="bold"
    />

Answer 2

您是否尝试将RelativeLayout高度设置为wrap_content而不是match_parent？

Answer 3

在dictionary_list_row.xml

中

在相对布局中

android:layout_height="wrap_content"

TextView

android:layout_height="wrap_content"

和

<android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical" />

Answer 4

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:focusable="true"
            android:clickable="true"
            android:background="?android:attr/selectableItemBackground"
            android:orientation="vertical">
    <TextView
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:id="@+id/vocab"
    android:textSize="32dp"
    android:textStyle="bold"
    />
  </RelativeLayout>