主要就是activity和recycview,recycview和adapter;
主要就是fragment和recycview,recycview和adapter;
1.在build.gradle添加RecyclerView的依赖,因为RecyclerView不是内置在android系统中的,请注意版本要一致
dependencies { implementation fileTree(dir: 'libs', include: ['*.jar']) implementation 'com.android.support:appcompat-v7:27.1.1' implementation 'com.android.support.constraint:constraint-layout:1.0.2' testImplementation 'junit:junit:4.12' androidTestImplementation 'com.android.support.test:runner:1.0.1' androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1' compile 'com.android.support:recyclerview-v7:27.1.1' }
2.在布局中添加RecyclerView组件
<?xml version="1.0" encoding="utf-8"?> <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="match_parent" tools:context=".MainActivity"> <android.support.v7.widget.RecyclerView android:id="@+id/recycler_view" android:layout_width="match_parent" android:layout_height="match_parent"> </android.support.v7.widget.RecyclerView> </LinearLayout>
public class FruitAdapter extends RecyclerView.Adapter<FruitAdapter.ViewHolder> { private List<Fruit> mFruitList; static class ViewHolder extends RecyclerView.ViewHolder { View fruitView; ImageView fruitImage; TextView fruitName; public ViewHolder(View view) { super(view); fruitView = view; fruitImage = (ImageView) view.findViewById(R.id.fruit_image); fruitName = (TextView) view.findViewById(R.id.fruit_name); } } public FruitAdapter(List<Fruit> fruitList) { mFruitList = fruitList; } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fruit_item, parent, false); final ViewHolder holder = new ViewHolder(view); holder.fruitView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Toast.makeText(v.getContext(), "you clicked view " + fruit.getName(), Toast.LENGTH_SHORT).show(); } }); holder.fruitView.setOnLongClickListener( new View.OnLongClickListener() { @Override public boolean onLongClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Toast.makeText(v.getContext(), "你长时间按住了我 " + fruit.getName(), Toast.LENGTH_SHORT).show(); //这里必须返回true,否则有可能引起点击事件混乱,因为优先响应的是长按事件,返回true可以在长按事件响应失败时把该点击事件消化掉,避免出错 return true; } } ); holder.fruitImage.setOnLongClickListener( new View.OnLongClickListener() { @Override public boolean onLongClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Toast.makeText(v.getContext(), "你长时间按住了我 " + fruit.getName(), Toast.LENGTH_SHORT).show(); return true; } } ); holder.fruitImage.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { int position = holder.getAdapterPosition(); Fruit fruit = mFruitList.get(position); Toast.makeText(v.getContext(), "you clicked image " + fruit.getName(), Toast.LENGTH_SHORT).show(); } }); return holder; } //这个方法主要用于适配渲染数据到View中 @Override public void onBindViewHolder(ViewHolder holder, int position) { Fruit fruit = mFruitList.get(position); holder.fruitImage.setImageResource(fruit.getImageId()); holder.fruitName.setText(fruit.getName()); } //BaseAdapter的getCount方法了,即总共有多少个条目 @Override public int getItemCount() { return mFruitList.size(); } }
3.写一下Bean
public class Fruit { private String name; private int imageId; public Fruit(String name, int imageId) { this.name = name; this.imageId = imageId; } public String getName() { return name; } public int getImageId() { return imageId; } }
4.在Activity里面写逻辑
public class MainActivity extends AppCompatActivity { private List<Fruit> fruitList = new ArrayList<Fruit>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initFruits(); RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view); // 设置布局管理器 //瀑布流 StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL); /*// 设置布局管理器 //垂直分布和横向分布 LinearLayoutManager.HORIZONTAL VERTICAL LinearLayoutManager layoutManager = new LinearLayoutManager(this); layoutManager.setOrientation(LinearLayoutManager.VERTICAL);*/ recyclerView.setLayoutManager(layoutManager); FruitAdapter adapter = new FruitAdapter(fruitList); recyclerView.setAdapter(adapter); } private void initFruits() { for (int i = 0; i < 5; i++) { Fruit apple = new Fruit(getRandomLengthName("Apple"), R.drawable.apple_pic); fruitList.add(apple); Fruit banana = new Fruit(getRandomLengthName("Banana"), R.drawable.banana_pic); fruitList.add(banana); Fruit orange = new Fruit(getRandomLengthName("Orange"), R.drawable.orange_pic); fruitList.add(orange); Fruit watermelon = new Fruit(getRandomLengthName("Watermelon"), R.drawable.watermelon_pic); fruitList.add(watermelon); Fruit pear = new Fruit(getRandomLengthName("Pear"), R.drawable.pear_pic); fruitList.add(pear); Fruit grape = new Fruit(getRandomLengthName("Grape"), R.drawable.grape_pic); fruitList.add(grape); Fruit pineapple = new Fruit(getRandomLengthName("Pineapple"), R.drawable.pineapple_pic); fruitList.add(pineapple); Fruit strawberry = new Fruit(getRandomLengthName("Strawberry"), R.drawable.strawberry_pic); fruitList.add(strawberry); Fruit cherry = new Fruit(getRandomLengthName("Cherry"), R.drawable.cherry_pic); fruitList.add(cherry); Fruit mango = new Fruit(getRandomLengthName("Mango"), R.drawable.mango_pic); fruitList.add(mango); } } private String getRandomLengthName(String name) { Random random = new Random(); //nextInt 产生一个大于0小于()内参数的随机数 int length = random.nextInt(20) + 1; StringBuilder builder = new StringBuilder(); for (int i = 0; i < length; i++) { builder.append(name); } return builder.toString(); } }
在Fragment里面写逻辑
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:fitsSystemWindows="true" android:orientation="vertical"> <android.support.v7.widget.RecyclerView android:id="@+id/collect_recyclerView" android:layout_width="match_parent" android:layout_height="match_parent"> </android.support.v7.widget.RecyclerView> </LinearLayout>
在fragment中定义使用
public class CollectFragment extends Fragment { private View view;//定义view用来设置fragment的layout public RecyclerView mCollectRecyclerView;//定义RecyclerView //定义以goodsentity实体类为对象的数据集合 private ArrayList<GoodsEntity> goodsEntityList = new ArrayList<GoodsEntity>(); //自定义recyclerveiw的适配器 private CollectRecycleAdapter mCollectRecyclerAdapter; @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { //获取fragment的layout view = inflater.inflate(R.layout.collect_page, container, false); //对recycleview进行配置 initRecyclerView(); //模拟数据 initData(); return view; } /** * TODO 模拟数据 */ private void initData() { for (int i=0;i<10;i++){ GoodsEntity goodsEntity=new GoodsEntity(); goodsEntity.setGoodsName("模拟数据"+i); goodsEntity.setGoodsPrice("100"+i); goodsEntityList.add(goodsEntity); } } /** * TODO 对recycleview进行配置 */ private void initRecyclerView() { //获取RecyclerView mCollectRecyclerView=(RecyclerView)view.findViewById(R.id.collect_recyclerView); //创建adapter mCollectRecyclerAdapter = new CollectRecycleAdapter(getActivity(), goodsEntityList); //给RecyclerView设置adapter mCollectRecyclerView.setAdapter(mCollectRecyclerAdapter); //设置layoutManager,可以设置显示效果,是线性布局、grid布局,还是瀑布流布局 //参数是:上下文、列表方向(横向还是纵向)、是否倒叙 mCollectRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false)); //设置item的分割线 mCollectRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(),DividerItemDecoration.VERTICAL)); //RecyclerView中没有item的监听事件,需要自己在适配器中写一个监听事件的接口。参数根据自定义 mCollectRecyclerAdapter.setOnItemClickListener(new CollectRecycleAdapter.OnItemClickListener() { @Override public void OnItemClick(View view, GoodsEntity data) { //此处进行监听事件的业务处理 Toast.makeText(getActivity(),"我是item",Toast.LENGTH_SHORT).show(); } }); } }
设置RecyclerView的适配器
public class CollectRecycleAdapter extends RecyclerView.Adapter<CollectRecycleAdapter.myViewHodler> { private Context context; private ArrayList<GoodsEntity> goodsEntityList; //创建构造函数 public CollectRecycleAdapter(Context context, ArrayList<GoodsEntity> goodsEntityList) { //将传递过来的数据,赋值给本地变量 this.context = context;//上下文 this.goodsEntityList = goodsEntityList;//实体类数据ArrayList } /** * 创建viewhodler,相当于listview中getview中的创建view和viewhodler * * @param parent * @param viewType * @return */ @Override public myViewHodler onCreateViewHolder(ViewGroup parent, int viewType) { //创建自定义布局 View itemView = View.inflate(context, R.layout.item_layout, null); return new myViewHodler(itemView); } /** * 绑定数据,数据与view绑定 * * @param holder * @param position */ @Override public void onBindViewHolder(myViewHodler holder, int position) { //根据点击位置绑定数据 GoodsEntity data = goodsEntityList.get(position); // holder.mItemGoodsImg; holder.mItemGoodsName.setText(data.goodsName);//获取实体类中的name字段并设置 holder.mItemGoodsPrice.setText(data.goodsPrice);//获取实体类中的price字段并设置 } /** * 得到总条数 * * @return */ @Override public int getItemCount() { return goodsEntityList.size(); } //自定义viewhodler class myViewHodler extends RecyclerView.ViewHolder { private ImageView mItemGoodsImg; private TextView mItemGoodsName; private TextView mItemGoodsPrice; public myViewHodler(View itemView) { super(itemView); mItemGoodsImg = (ImageView) itemView.findViewById(R.id.item_goods_img); mItemGoodsName = (TextView) itemView.findViewById(R.id.item_goods_name); mItemGoodsPrice = (TextView) itemView.findViewById(R.id.item_goods_price); //点击事件放在adapter中使用,也可以写个接口在activity中调用 //方法一:在adapter中设置点击事件 itemView.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //可以选择直接在本位置直接写业务处理 //Toast.makeText(context,"点击了xxx",Toast.LENGTH_SHORT).show(); //此处回传点击监听事件 if(onItemClickListener!=null){ onItemClickListener.OnItemClick(v, goodsEntityList.get(getLayoutPosition())); } } }); } } /** * 设置item的监听事件的接口 */ public interface OnItemClickListener { /** * 接口中的点击每一项的实现方法,参数自己定义 * * @param view 点击的item的视图 * @param data 点击的item的数据 */ public void OnItemClick(View view, GoodsEntity data); } //需要外部访问,所以需要设置set方法,方便调用 private OnItemClickListener onItemClickListener; public void setOnItemClickListener(OnItemClickListener onItemClickListener) { this.onItemClickListener = onItemClickListener; } }
自定义实体类简单展示:
public class GoodsEntity implements Serializable { public String imgPath;//图片地址 public String goodsName;//货物名称 public String goodsPrice;//货物价格 public GoodsEntity() { } public GoodsEntity(String imgPath, String goodsName, String goodsPrice) { this.imgPath = imgPath; this.goodsName = goodsName; this.goodsPrice = goodsPrice; } public String getImgPath() { return imgPath; } public void setImgPath(String imgPath) { this.imgPath = imgPath; } public String getGoodsName() { return goodsName; } public void setGoodsName(String goodsName) { this.goodsName = goodsName; } public String getGoodsPrice() { return goodsPrice; } public void setGoodsPrice(String goodsPrice) { this.goodsPrice = goodsPrice; } @Override public String toString() { return "GoodsEntity{" + "imgPath='" + imgPath + '\'' + ", goodsName='" + goodsName + '\'' + ", goodsPrice='" + goodsPrice + '\'' + '}'; } }