android -------- Data Binding的使用RecyclerView _recyclerview

最是人间留不住，朱颜辞镜花辞树。这篇文章主要讲述android -------- Data Binding的使用RecyclerView相关的知识，希望能为你提供帮助。
今天来说说DataBinding在列表RecyclerView中的使用
列表绑定
App中经常用到列表展示，Data Binding在列表中一样可以扮演重要的作用，直接绑定数据和事件到每一个列表的item。

RecyclerView
过去我们往往会使用ListView、GridView、或者GitHub上一些自定义的View来做瀑布流。自从RecyclerView出现后，我们有了新选择，只需要使用LayoutManager就可以。
RecyclerView内置的垃圾回收，ViewHolder、ItemDecoration装饰器机制都让我们可以毫不犹豫地替换掉原来的ListView和GridView。

主布局：

< ?xml version="1.0" encoding="utf-8"?> < layout xmlns:android="http://schemas.android.com/apk/res/android"> < data> < /data> < LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> < LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> < Button android:id="@+id/btn_demo8_add" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:text="添加" /> < Button android:id="@+id/btn_demo8_refresh" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginLeft="10dp" android:layout_weight="1" android:text="刷新" /> < Button android:id="@+id/btn_demo8_delete" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginLeft="10dp" android:layout_weight="1" android:text="删除" /> < /LinearLayout> < android.support.v7.widget.RecyclerView android:id="@+id/demo8_recyclerview" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp"> < /android.support.v7.widget.RecyclerView> < /LinearLayout> < /layout>

item布局：

< ?xml version="1.0" encoding="utf-8"?> < layout xmlns:android="http://schemas.android.com/apk/res/android"> < data> < import type="com.zhangqie.databinding.demo8.UserObservableBean"/> < variable name="userObserBean" type="UserObservableBean"/> < /data> < LinearLayout android:layout_width="match_parent" android:layout_height="100dp" android:descendantFocusability="blocksDescendants" android:orientation="horizontal"> < LinearLayout android:layout_width="wrap_content" android:layout_weight="1" android:layout_height="match_parent" android:orientation="vertical" android:gravity="center" > < TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{`编号：` + userObserBean.userId }" /> < TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{`姓名：` +userObserBean.userName}" android:layout_marginTop="5dp" /> < /LinearLayout> < LinearLayout android:layout_width="wrap_content" android:layout_weight="1" android:layout_height="match_parent" android:orientation="vertical" android:gravity="center" > < TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{`年龄：` +userObserBean.userAge}" /> < !--一定要使用1f而不能是使用1 ，类型必须相对应--> < TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:text="@{`性别：` + (userObserBean.userSex == 1f ? `男` : `女`)}" /> < /LinearLayout> < LinearLayout android:layout_width="wrap_content" android:layout_height="match_parent" android:orientation="vertical" android:layout_marginRight="10dp" android:paddingBottom="10dp" > < Button android:id="@+id/btn_update" android:layout_width="wrap_content" android:layout_height="40dp" android:text="修改数据" /> < Button android:id="@+id/btn_delete" android:layout_width="wrap_content" android:layout_height="40dp" android:layout_marginTop="5dp" android:text="删除数据" /> < /LinearLayout> < /LinearLayout> < /layout>

ViewHolder

public class RecyclerViewHolder extends RecyclerView.ViewHolder {public Item8MvvmBinding getItem8MvvmBinding() { return item8MvvmBinding; }public void setItem8MvvmBinding(Item8MvvmBinding item8MvvmBinding) { this.item8MvvmBinding = item8MvvmBinding; }//这里只要给RecyclerView.ViewHolder返回一个view就可以，所以我们将构造方法中传入databinding Item8MvvmBinding item8MvvmBinding; public RecyclerViewHolder(Item8MvvmBinding item8MvvmBinding) { super(item8MvvmBinding.getRoot()); this.item8MvvmBinding = item8MvvmBinding; } }

adapter：

public class RecyclerViewAdapter extends RecyclerView.Adapter< RecyclerViewHolder> implements View.OnClickListener{private List< UserObservableBean> list; private Random random = new Random(System.currentTimeMillis()); public RecyclerViewAdapter(List< UserObservableBean> list) { this.list = list; }public OnItemOnClickListener getOnItemOnClickListener() { return onItemOnClickListener; }public void setOnItemOnClickListener(OnItemOnClickListener onItemOnClickListener) { this.onItemOnClickListener = onItemOnClickListener; }private OnItemOnClickListener onItemOnClickListener; public interface OnItemOnClickListener{ void onItemClick(View view, int position); }@Override public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { Item8MvvmBinding item8MvvmBinding = DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()), R.layout.item8_mvvm,parent,false); item8MvvmBinding.getRoot().setOnClickListener(this); return new RecyclerViewHolder(item8MvvmBinding); }@Override public void onBindViewHolder(RecyclerViewHolder holder, int position) { Item8MvvmBinding item8MvvmBinding = holder.getItem8MvvmBinding(); UserObservableBean userObservableBean = list.get(position); item8MvvmBinding.setVariable(com.zhangqie.databinding.BR.userObserBean,userObservableBean); //将position保存在itemView的Tag中，以便点击时进行获取 item8MvvmBinding.getRoot().setTag(position); item8MvvmBinding.btnUpdate.setOnClickListener(new OnBtnClickListener(1, userObservableBean)); item8MvvmBinding.btnDelete.setOnClickListener(new OnBtnClickListener(2, position)); // 立刻执行绑定 item8MvvmBinding.executePendingBindings(); }@Override public int getItemCount() { return list.size(); }public void addData(UserObservableBean userObservableBean){ int position = random.nextInt(list.size()+1); list.add(position,userObservableBean); notifyItemInserted(position); //添加操作的动画 }public void deleteData(int positionn){ if (list.size() == 0){ return; } int position = random.nextInt(list.size()); list.remove(position); notifyItemRemoved(position); //删除操作的动画 }@Override public void onClick(View view) { if (onItemOnClickListener != null) onItemOnClickListener.onItemClick(view, (int) view.getTag()); }private class OnBtnClickListener implements View.OnClickListener{private int stats; //1,修改；2，删除 private UserObservableBean userBean; private int position; OnBtnClickListener(int stats, UserObservableBean userBean) { this.stats = stats; this.userBean = userBean; }OnBtnClickListener(int stats, int position) { this.stats = stats; this.position = position; }@Override public void onClick(View v) { switch (stats) { case 1: userBean.userName.set("修改后的名字"); break; case 2: list.remove(position); notifyDataSetChanged(); break; } } }}

主Activity：

public class Demo8 extends AppCompatActivity {Demo8Binding demo8Binding; RecyclerViewAdapter recyclerViewAdapter; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); demo8Binding = DataBindingUtil.setContentView(this, R.layout.demo8); initView(); }private void initView(){ RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this); demo8Binding.demo8Recyclerview.setLayoutManager(layoutManager); recyclerViewAdapter = new RecyclerViewAdapter(initObservableData()); demo8Binding.demo8Recyclerview.setAdapter(recyclerViewAdapter); //item的点击事件 recyclerViewAdapter.setOnItemOnClickListener(new RecyclerViewAdapter.OnItemOnClickListener() { @Override public void onItemClick(View view, int position) { Toast.makeText(Demo8.this, "行数：" + position, Toast.LENGTH_LONG).show(); } }); demo8Binding.btnDemo8Add.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { UserObservableBean userBean = new UserObservableBean(); userBean.userId.set(8); userBean.userName.set("切切心语"+8); userBean.userAge.set(25); userBean.userSex.set(8 % 2 == 0 ? 1 : 0); recyclerViewAdapter.addData(userBean); } }); demo8Binding.btnDemo8Refresh.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { recyclerViewAdapter.notifyDataSetChanged(); } }); demo8Binding.btnDemo8Delete.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { recyclerViewAdapter.deleteData(1); } }); }//初始化测试数据 private List< UserObservableBean> initObservableData() { List< UserObservableBean> list = new ArrayList< > (); for (int i = 1; i < 6; i++) { UserObservableBean userBean = new UserObservableBean(); userBean.userId.set(i); userBean.userName.set("切切心语"+i); userBean.userAge.set(18 + i); userBean.userSex.set(i % 2 == 0 ? 1 : 0); list.add(userBean); } return list; } }

自己练习的一个RecyclerView + Databinding使用

效果如图：