为什么我的Android RelativeLayout中的元素在ListView中膨胀时没有显示？

Question

我有一个自定义视图，我把它看起来像Google Now卡。这是Android Studio中的样子：

忽略Android Studio渲染屏幕其余部分的事实;视图只是由底部的阴影所包围的矩形。如果我将其设置为主内容视图并在运行时只是膨胀一个，它看起来是正确的。如果我在运行时将一个作为ListView的一部分膨胀，它看起来像这样：

消失的视图似乎有一个共同点，那就是它们附着在布局边缘以外的东西上。这是布局：

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="340dp"
            android:layout_height="260dp"
            android:clipToPadding="true"
            android:background="@drawable/card_background"
            android:minHeight="260dp"
            android:minWidth="340dp">


<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="4"
        android:id="@+id/textBeat"
        android:fontFamily="sans-serif-light"
        android:textSize="80sp"
        android:textColor="@android:color/holo_red_light"
        android:layout_above="@+id/linearLayout"
        android:layout_alignRight="@+id/buttonMenu"/>

<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="Card Title"
        android:id="@+id/textTitle"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="12dp"
        android:textColor="@android:color/darker_gray"
        android:fontFamily="sans-serif-light"
        android:maxWidth="280dp"
        android:layout_alignParentTop="true"
        android:layout_marginTop="12dp"
        android:textSize="36sp"
        android:maxHeight="96dp"
        android:ellipsize="end"/>

<LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="48dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:id="@+id/linearLayout">

    <ImageButton
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:id="@+id/buttonToggle"
            android:layout_weight="1"
            android:background="@android:color/transparent"
            android:src="@drawable/ic_launcher"/>

    <View
            android:layout_width="1dp"
            android:layout_height="fill_parent"
            android:layout_marginTop="8dp"
            android:layout_marginBottom="8dp"
            android:background="@android:color/darker_gray"/>

    <ImageButton
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:id="@+id/buttonDelete"
            android:layout_weight="1"
            android:background="@android:color/transparent"
            android:src="@drawable/ic_launcher"/>
</LinearLayout>

<ImageButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"
        android:background="@android:color/transparent"
        android:onClick="showPopup"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:layout_marginTop="12dp"
        android:layout_marginRight="12dp"
        android:id="@+id/buttonMenu"/>

<Button
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:text="200"
        android:id="@+id/buttonTempo"
        android:layout_above="@+id/linearLayout"
        android:layout_alignLeft="@+id/textTitle"
        android:background="@android:color/transparent"
        android:textColor="@android:color/holo_blue_light"/>

<Button
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:text="4"
        android:id="@+id/buttonSignature"
        android:background="@android:color/transparent"
        android:textColor="@android:color/holo_blue_light"
        android:layout_above="@+id/linearLayout"
        android:layout_toRightOf="@+id/buttonTempo"/>

<Button
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:text="2"
        android:id="@+id/buttonSubdiv"
        android:background="@android:color/transparent"
        android:textColor="@android:color/holo_blue_light"
        android:layout_above="@+id/linearLayout"
        android:layout_toRightOf="@+id/buttonSignature"/>

<ImageView
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:id="@+id/iconTempo"
        android:layout_above="@+id/buttonTempo"
        android:layout_alignLeft="@+id/buttonTempo"
        android:src="@drawable/ic_launcher"
        android:paddingTop="8dp"/>

<ImageView
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:id="@+id/iconSignature"
        android:src="@drawable/ic_launcher"
        android:layout_above="@+id/buttonTempo"
        android:layout_toRightOf="@+id/buttonTempo"
        android:paddingTop="8dp"/>

<ImageView
        android:layout_width="48dp"
        android:layout_height="48dp"
        android:id="@+id/iconSubdiv"
        android:src="@drawable/ic_launcher"
        android:layout_above="@+id/buttonSignature"
        android:layout_toRightOf="@+id/buttonSignature"
        android:paddingTop="8dp"/>

这是适配器：

public class CardAdapter extends BaseAdapter {
private static final String TAG = "RhythmCards";

private final Context mContext;
private final ArrayList<Card> mCards;

public CardAdapter(Context context, ArrayList<Card> cards) {
    mContext = context;
    mCards = cards;
}

static class ViewHolder {
    public TextView title;
    public Button tempo;
    public Button signature;
    public Button subdivision;
    public TextView beat;
}

@Override
public View getView(int position, View convertView, ViewGroup viewGroup) {
    ViewHolder holder;


    // If the row passed in is null, we must inflate and populate a new view.
    if (convertView == null) {
        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = inflater.inflate(R.layout.card_layout, null);

        holder = new ViewHolder();

        // Put references to views contained in card into holder
        holder.title = (TextView) convertView.findViewById(R.id.textTitle);
        holder.tempo = (Button) convertView.findViewById(R.id.buttonTempo);
        holder.signature = (Button) convertView.findViewById(R.id.buttonSignature);
        holder.subdivision = (Button) convertView.findViewById(R.id.buttonSubdiv);
        holder.beat = (TextView) convertView.findViewById(R.id.textBeat);

        convertView.setTag(holder);
    } else {
        // Otherwise, we use the holder attached to the row passed in
        holder = (ViewHolder) convertView.getTag();
    }

    return convertView;
}

@Override
public int getCount() {
    return mCards.size();
}

@Override
public Object getItem(int position) {
    return mCards.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}
}

是什么让这些观点不显示？