RecyclerView 中只显示一项

Question

我正在调试并从服务器获得正确数量的项目。并且它还会调用与项目大小一样多的 onCreateViewholder 和 onBindViewHolder。

但是，我的 RecyclerView 只显示列表中的一项。

我搜索后的大部分问题是当 RecyclerView 的高度为match_parent. 我的match_parent也是。所以，我把它改成了wrap_content. 但它得到正确的项目数量和正确的项目数据。但是不能在 Recycler 视图中显示所有时间。

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    ArrayList<MyData> MyDataArrayList;

    public static class MyViewHolder extends RecyclerView.ViewHolder {
        TextView userId;

        MyViewHolder(View view) {
            super(view);
            Log.d(TAG, "created()");
            tvUserID = view.findViewById(R.id.textview_myitem);
        }
    }

    public MyAdapter (ArrayList<MyData> myDataArrayList) {
        Log.d(TAG, "new MyAdapter instance created");
        this.myDataArrayList = myDataArrayList;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        Log.d(TAG, "onCreateViewHolder()");
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_item, parent, false);

        return new MyViewHolder(v);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        Log.d(TAG, "onBindViewHolder()=\nposition: " + position + ",\nitem: " + myDataArrayList.get(position).toString());

        MyViewHolder myViewHolder = (MyViewHolder) holder;

        Log.d(TAG, "getItemCount(): " + getItemCount());
        try {
            String username = myDataArrayList.get(position).getUser();
            myViewHolder.userId.setText(username);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

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

recyclerView = findViewById(R.id.my_recycler_view);
layoutManager = new LinearLayoutManager(MyActivity.this);
myAdapter = new myAdapter(myDataArrayList);
recyclerView.setAdapter(myAdapter);
recyclerView.setLayoutManager(layoutManager);

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

这是my_item.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/textview_myitem"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:textSize="25dp"
        android:text="username"
        android:gravity="center_vertical"
        android:paddingLeft="15dp" />
</LinearLayout>

这是什么问题？

Answer 1

My_item.xml 具有 matchparent 的宽度和高度，更改高度以包装内容。