[Android]RecyclerView shows only one item

Phenomenon

I want to read data from the database and display it in a list with RecyclerView. There should be more than one registered in the database, but only one is displayed in RecyclerView. Unlike the last time, getItemCount () of RecyclerView.Adapter is set properly.

Cause

Each view is defined in the xml file and inflated with the newView method of the constructor. In this source xml file, layout_height of the outermost layout was match_parent. After changing to wrap_content, all items were displayed safely.

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {

    View inflate= LayoutInflater.from(context).inflate(R.layout.row, parent, false);

    return inflate;
}

row.xml

<LinearLayout 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="wrap_content"  //here！