Android開(kāi)發(fā)學(xué)習(xí)教程（19）- Android RecyclerView列表用法
—— 放棄不難，但堅(jiān)持一定很酷。
RecyclerView是什么
RecyclerView是一個(gè)和ListView一樣用來(lái)顯示大量數(shù)據(jù)列表但是比ListView更高效的列表控件。關(guān)于ListView的學(xué)習(xí)請(qǐng)見(jiàn)上一篇文章。
RecyclerView有什么用
RecyclerView用來(lái)更高效的展示大量數(shù)據(jù)列表。
RecyclerView怎么用
1. 導(dǎo)入依賴(lài)包
implementation?'androidx.recyclerview:recyclerview:1.1.0'2. 布局中加入RecyclerView控件
<androidx.recyclerview.widget.RecyclerView????android:id="@+id/recyclerview"????android:layout_width="match_parent"????android:layout_height="match_parent"?/>3. 實(shí)例化RecycleView并設(shè)置布局方式
RecyclerView recyclerView = findViewById(R.id.recyclerview);LinearLayoutManager layoutManager =?new?LinearLayoutManager(this);layoutManager.setOrientation(LinearLayoutManager.VERTICAL);recyclerView.setLayoutManager(layoutManager);其中LinearLayoutManager就是類(lèi)似ListView的功能，列表上下滾動(dòng)（LinearLayoutManager.VERTICAL）或者左右滾動(dòng)（LinearLayoutManager.VERTICAL）。除了可以設(shè)置為L(zhǎng)inearLayoutManager還可以設(shè)置GridLayoutManager、StaggeredGridLayoutMnager，GridLayoutManager是網(wǎng)格擺放，而StaggeredGridLayoutMnager則是瀑布流擺放。
4. 獲取數(shù)據(jù)，定義自己的數(shù)據(jù)適配器并設(shè)置到RecyclerView上
自定義BaseAdapter可以展示任意類(lèi)型的數(shù)據(jù)列表項(xiàng)，其實(shí)上面SimpleAdapter和ArrayAdapter都是繼承自BaseAdapter，區(qū)別在于getView方法，SimpleAdapter和ArrayAdapter的getView讀者可以自行查看源碼，基本和上面截取的一小段差不多。我們來(lái)看自定義BaseAdapter的用法：
????// 獲取數(shù)據(jù)，這里模擬獲取到了20條數(shù)據(jù)????stringList =?new?ArrayList<>();????for?(int?i =?0; i <?20; i++) {????????stringList.add("Item"?+ i);????}????recyclerView.setAdapter(new?MyAdapter());????// 定義自己的數(shù)據(jù)適配器????class?MyAdapter?extends?RecyclerView.Adapter<myadapter.myviewholder> {????????@NonNull????????@Override????????public?MyAdapter.MyViewHolder onCreateViewHolder(@NonNull?ViewGroup parent,?int?viewType) {????????????View itemView = LayoutInflater.from(MainActivity.this).inflate(R.layout.item_recyclerview, parent,?false);????????????return?new?MyViewHolder(itemView);????????}????????@Override????????public?void?onBindViewHolder(@NonNull?MyAdapter.MyViewHolder holder,?int?position) {????????????holder.tvName.setText(stringList.get(position));????????}????????@Override????????public?int?getItemCount() {????????????return?stringList ==?null???0?: stringList.size();????????}????// 定義緩存ViewHolder????????class?MyViewHolder?extends?RecyclerView.ViewHolder {????????????public?TextView tvName;????????????public?MyViewHolder(View itemView) {????????????????super(itemView);????????????????tvName = itemView.findViewById(R.id.tv_name);????????????????tvName.setOnClickListener(new?View.OnClickListener() {????????????????????@Override????????????????????public?void?onClick(View v) {????????????????????????Toast.makeText(MainActivity.this, tvName.getText(), Toast.LENGTH_SHORT).show();????????????????????}????????????????});????????????}????????}????}</myadapter.myviewholder>運(yùn)行效果：
源碼鏈接：https://yunjunet.cn/876790.html
