RecyclerView的相关用法简介

来源：互联网发布：有个软件ktv软件叫什么编辑：程序博客网时间：2024/06/06 05:13
public class MainActivity extends AppCompatActivity {    private RecyclerView mRecyclerView;    List<String> mDatas;    MyAdapter mAdapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview);        initData();//初始化数据        mAdapter = new MyAdapter(mDatas, this);//初始化Adapter(设配器)        mRecyclerView.setAdapter(mAdapter);//设置Adapter        //设置分隔线//        mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));        //必须要设置布局管理器,不然界面是空的        ////////////////////////////////   完成listview的效果   ////////////////////////////////        LinearLayoutManager layout = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,true);//        mRecyclerView.setLayoutManager(layout);        ////////////////////////////////   完成listview的效果   //////////////////////////////        //设置gridview 的效果//        mRecyclerView.setLayoutManager(new GridLayoutManager(this,3));        //这里如果是水平的,而item的宽度item的个数不足以填充宽度,item与item之间会自动有空白来代替        mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL));        mAdapter.setOnItemClickListener(new MyAdapter.OnItemClickListener() {  //RecyclerView的item点击事件            @Override            public void onItemClickListener(int position, View v) {                mAdapter.add(position);            }            @Override            public void onItemLongClickListener(int position, View v) {                mAdapter.delete(position);            }        });    }    private void initData() {        mDatas = new ArrayList<>();        for (int i = 'A'; i < 'G'; i++) {            mDatas.add((char) i + "");        }    }}Adapter类的代码:public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {    List<String> mList;    Context mContext;    private LayoutInflater mInflater;    public MyAdapter(List<String> list, Context context) {        mList = list;        mContext = context;        mInflater = LayoutInflater.from(mContext);    }    @Override    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        //注意这里的参数只能改第一个参数resource,只能使用LayoutInflater.inflate.(resource,viewGroup,attachToRoot);        View view = mInflater.inflate(R.layout.item, parent, false);        MyViewHolder myViewHolder = new MyViewHolder(view);        return myViewHolder;    }    public interface OnItemClickListener {        void onItemClickListener(int position,View v);        void onItemLongClickListener(int position,View v);    }    private OnItemClickListener mListener;    public void setOnItemClickListener(OnItemClickListener listener) {        mListener = listener;    }    @Override    public void onBindViewHolder(final MyViewHolder holder, final int position) {        if (mListener != null) {            holder.itemView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    int layoutPosition = holder.getLayoutPosition();                    mListener.onItemClickListener(layoutPosition,v);//要用holder.getLayoutPosition()的数,得到布局上的item的排序                }            });            holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {                @Override                public boolean onLongClick(View v) {                    int layoutPosition = holder.getLayoutPosition();                    mListener.onItemLongClickListener(layoutPosition,v);//这个position是不准确的,                    // 因为当增删item,position会不准确,还是会依照一开始的条目排序,有时position并不是会随item改变而变                    return false;                }            });        }        holder.mTv.setText(mList.get(position));        //在这里设置随机高度        ViewGroup.LayoutParams layoutParams = holder.itemView.getLayoutParams();        layoutParams.height = 100 + r.nextInt(200);        holder.itemView.setLayoutParams(layoutParams);    }    Random r = new Random();    @Override    public int getItemCount() {        if (mList == null)            return 0;        return mList.size();    }    public void add(int position) {        mList.add(position, "insert one");        notifyItemInserted(position);//代表插入第几个item    }    public void delete(int position) {        mList.remove(position);        notifyItemRemoved(position);    }}class MyViewHolder extends RecyclerView.ViewHolder {    TextView mTv;    public MyViewHolder(View itemView) {        super(itemView);        mTv = (TextView) itemView.findViewById(R.id.tv);    }}
item布局文件代码里面就一个TextView自己可以修改:


<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/activity_main"    android:layout_width="72dp"    android:layout_margin="3dp"    android:orientation="vertical"    android:layout_height="50dp"    android:background="#5f00">    <TextView        android:id="@+id/tv"        android:gravity="center"        android:text="A"        android:textColor="#fff"        android:layout_width="72dp"        android:layout_height="50dp"/></LinearLayout>

如果要简单自定义分隔线,可以在src/res/drawable里画些样式:
<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"       android:shape="rectangle">    <size android:height="4dp"></size>    <gradient        android:centerColor="#0f0"        android:endColor="#00f"        android:startColor="#f00"        android:type="linear"></gradient></shape>
记得要生效的话必须要在使用的主题里添加一行代码:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">    <!--这是从DividerItemDecoration里面的属性来的,在你使用的主题里改变一下就可以-->    <item name="android:listDivider">@drawable/divider02(这里是自己画的xml文件名)</item></style>

总结:RecyclerView比较强大,但是要自己实现item点击事件,主要的item里的position要注意,使用这个方法holder.getLayoutPosition()来替代position,还有的话是public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {    //注意这里的参数只能改第一个参数resource,只能使用LayoutInflater.inflate.(resource,viewGroup,attachToRoot);    View view = mInflater.inflate(R.layout.item, parent, false);//mInflater=android.view.LayoutInflater.from(mContext)    MyViewHolder myViewHolder = new MyViewHolder(view);    return myViewHolder;}不可以使用View.Inflate()方法
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