Question

我对sub api21设备有一个讨厌的问题。我正在使用 RecyclerView.Adapter 适配器来充气 android.support.v7.widget.CardView 。这个想法是卡片只会添加卡片上的信息。如果没有信息，卡片根本不显示。所以我以编程方式创建这些卡片。

以下是api21和api19的截屏 api21 api19

注意api19如何显示没有值的卡片。我认为问题是由适配器调用onCreateViewHolder而没有值。有没有办法绕过onCreate？还是onBind？或者有没有办法让sub api21处理卡有点不同？

CardView XML

<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/card_info"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clickable="false"
android:focusable="true"
card_view:cardCornerRadius="5dp"
android:layout_margin="5dp"
card_view:cardUseCompatPadding="true">

<LinearLayout
    android:id="@+id/card_info_lin"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"/>

适配器

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
   switch(viewType) {
       case VIEW_ENGINE:
            itemViewEngine = LayoutInflater
                    .from(viewGroup.getContext())
                    .inflate(R.layout.card_info, viewGroup, false);
            cardInfo.clear();

            return new ViewHolderEngine(itemViewEngine, cardInfo);

        case VIEW_TIRES:
            itemViewTires = LayoutInflater
                    .from(viewGroup.getContext())
                    .inflate(R.layout.card_info, viewGroup, false);
            cardInfo.clear();

            return new ViewHolderTires(itemViewTires, cardInfo);

        default: //General
            itemViewGeneral = LayoutInflater
                    .from(viewGroup.getContext())
                    .inflate(R.layout.card_info, viewGroup, false);
            cardInfo.clear();

            return new ViewHolderGeneral(itemViewGeneral, cardInfo);
    }
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int i) {
    cardInfo = vehicleInfo.get(i);
    switch (getItemViewType(i)) {
        case VIEW_GENERAL:
            new ViewHolderGeneral(itemViewGeneral, cardInfo);

            break;

        case VIEW_ENGINE:
            new ViewHolderEngine(itemViewEngine, cardInfo);

            break;

        case VIEW_TIRES:
            new ViewHolderTires(itemViewTires, cardInfo);

            break;
        }
    }
}

观看者类别（1/3）

    class ViewHolderGeneral extends RecyclerView.ViewHolder {
        private static final String TAG = "adapter_info_ViewHolder_gen";

        private TypedArray headerColors;
        private ArrayList<String> labels = new ArrayList<>();

        public ViewHolderGeneral(View view, final ArrayList<String> cardInfo) {
            super(view);

            View layout = view.findViewById(R.id.card_info_lin);

            DisplayMetrics metrics = layout.getContext().getResources().getDisplayMetrics();

...set up cards

Answer 1

您看到的差异很可能是由于CardView在子API21上使用自己的填充/阴影机制。解决这个问题的方法是不要让你的适配器报告它没有数据。换句话说，如果卡片因为项目为空而为空，则不要在计数中报告此项目（或跟踪它们）。

RecyclerView适配器显示空白cardview

1 个答案: