java - 如何将 ListView 转换为任何类型的简单水平滚动条？

Question

我正在向我的应用程序添加一个包含大约 10 个图标的启动器，并让它垂直工作，但找不到可靠的简单解决方案来旋转它，以便它水平滚动 10 个图标。

Java:

private PackageManager manager;
private List<AppDetail> apps;
private ListView list;

private void loadListView(){
    //list = (ListView)findViewById(R.id.apps_list);//was apps_list
    list = (ListView) findViewById(R.id.apps_list);//was apps_list

    ArrayAdapter<AppDetail> adapter = new ArrayAdapter<AppDetail>(this,
            R.layout.list_item,
            apps) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            if(convertView == null){
                convertView = getLayoutInflater().inflate(R.layout.list_item, null);
            }

            ImageView appIcon = (ImageView)convertView.findViewById(R.id.item_app_icon);
            appIcon.setImageDrawable(apps.get(position).icon);

            TextView appLabel = (TextView)convertView.findViewById(R.id.item_app_label);
            appLabel.setText(apps.get(position).label);

            TextView appName = (TextView)convertView.findViewById(R.id.item_app_name);
            appName.setText(apps.get(position).name);

            return convertView;
        }
    };
    list.setAdapter(adapter); //Put the list on the screen
}

XML 布局内部

<ListView
    android:id="@+id/apps_list"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true"
    android:layout_marginBottom="50dp"
    android:layout_marginEnd="29dp"
    android:orientation="horizontal"/>

我看到了一个叫做 Horizo​​ntalScrollView 的东西，但它似乎不是直接替代品，只是导致应用程序崩溃。

看起来我应该使用 RecyclerView 或者类似的东西。

Java:

private void loadListView(){


    mRecyclerView = (RecyclerView) findViewById(R.id.apps_list);
    ArrayAdapter<AppDetail> mAdapter = new ArrayAdapter<AppDetail>(this,
            R.layout.list_item,
            apps) {
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            if(convertView == null){
                convertView = getLayoutInflater().inflate(R.layout.list_item, null);
            }

            ImageView appIcon = (ImageView)convertView.findViewById(R.id.item_app_icon);
            appIcon.setImageDrawable(apps.get(position).icon);

            TextView appLabel = (TextView)convertView.findViewById(R.id.item_app_label);
            appLabel.setText(apps.get(position).label);

            TextView appName = (TextView)convertView.findViewById(R.id.item_app_name);
            appName.setText(apps.get(position).name);

            return convertView;
        }
    };
    mRecyclerView.setAdapter(mAdapter); //Put the list on the screen
}

XML:

<android.support.v7.widget.RecyclerView
    android:id="@+id/apps_list"
    android:layout_width="fill_parent"
    android:layout_height="match_parent"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true"
    android:layout_marginBottom="50dp"
    android:layout_marginEnd="29dp"
    android:orientation="horizontal"
    android:scrollbars="horizontal"/>

但我收到错误:

Error:(1212, 34) error: incompatible types: ArrayAdapter cannot be converted to Adapter

感谢您的指导。

Answer 1

我已将您的 ListView 实现为回收器 View ，这是适配器:

public class SpecialAdapter extends RecyclerView.Adapter<SpecialAdapter.SpecialViewHolder> {

    private ArrayList<AppDetail> items;
    private Context context;
    private OnClickItem clickListener;

    public SpecialAdapter(ArrayList<AppDetail> items, Context context) {
        this.items = items;
        this.context = context;
    }

    public void setClickListener(OnClickItem clickListener) {
        this.clickListener = clickListener;
    }

    @NonNull
    @Override
    public SpecialViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
        return new SpecialViewHolder(v);
    }

    @Override
    public void onBindViewHolder(@NonNull SpecialViewHolder holder, int position) {
        holder.appIcon.setImageDrawable(items.get(position).icon);
        holder.appLabel.setText(items.get(position).label);
        holder.appName.setText(items.get(position).name);

    }

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

    class SpecialViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        ImageView appIcon;
        TextView appLabel;
        TextView appName;

        public SpecialViewHolder(View itemView) {
            super(itemView);
            appIcon = (ImageView) itemView.findViewById(R.id.item_app_icon);
            appLabel = (TextView) itemView.findViewById(R.id.item_app_label);
            appName = (TextView) itemView.findViewById(R.id.item_app_name);
             itemview.setOnClickListener(this);
        }

        @Override
        public void onClick(View v) {
            clickListener.onClickItem(getAdapterPosition());
        }
    }

    public interface OnClickItem {
        void onClickItem(int pos);
    }
}

要使用它，只需将 xml 中的 ListView 替换为 RecyclerVie 并使用:

public void setUpRecyclerView() {
    RecyclerView list = findViewById(R.id.apps_list);

    list.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
    SpecialAdapter adapter = new SpecialAdapter(apps,this);
    adapter.setClickListener(this);
    list.setAdapter(adapter);

}

此外，让您的 Activity 实现 OnClickItem，以便能够捕获列表中项目的点击。