Databinding打造RecyclerView万能适配器
这是最终效果图，用到了两种布局，Listview和Gridview形式的布局，其中垂直布局中显示了不同类型的item。下面示范如何使用，首先BaseRecyleAdapter如下：
public class BaseRecyleAdapter extends RecyclerView.Adapter {
public List data;//用?代表所有所有类型
Map hashMap;
public BaseRecyleAdapter(List data, Map hashMap) {
this.data = data;
this.hashMap = hashMap;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater from = LayoutInflater.from(parent.getContext());
ViewDataBinding inflate = DataBindingUtil.inflate(from, viewType, parent, false);//引入布局
return new ViewHolder(inflate);
}
/**
* map可以入参多个，也就是添加多布局，至少需要传一个，map中的key代表布局id,value对应布局中实体类的BR id
*默认取第一个，也就是把布局id取出来
* @param position
* @return
*/
@Override
public int getItemViewType(int position) {
Set integers = hashMap.keySet();
return integers.iterator().next();
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
Integer varid = hashMap.get(getItemViewType(position));
holder.dataBinding.setVariable(varid, data.get(position));//varid表示的是布局中数据名称对应的BR
if (onRecycleitemOnClic != null)//这里是实现item点击
holder.dataBinding.getRoot().setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
onRecycleitemOnClic.onItemClic(view, position);//开放接口
}
});
}
public OnRecycleitemOnClic getOnRecycleitemOnClic() {
return onRecycleitemOnClic;
}
public void setOnRecycleitemOnClic(OnRecycleitemOnClic onRecycleitemOnClic) {
this.onRecycleitemOnClic = onRecycleitemOnClic;
}
OnRecycleitemOnClic onRecycleitemOnClic;
public interface OnRecycleitemOnClic {
void onItemClic(View view, int position);
}
@Override
public int getItemCount() {
if (data == null)
return 0;
return data.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
ViewDataBinding dataBinding;
public ViewHolder(ViewDataBinding itemView) {
super(itemView.getRoot());
this.dataBinding = itemView;
}
}
}
下面是MainActivity:
public class MainActivity extends FragmentActivity {
private MainData mainData;
private TestListItemAdapter mainAdapter;
public BaseRecyleAdapter mainGridAdapter;
private List userInfo;
private LinearLayoutManager linearLayoutManager;
private GridLayoutManager gridLayoutManager;//gridview类型的布局
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initdatabinding();
}
private void initdatabinding() {
mainData = DataBindingUtil.setContentView(this, R.layout.activity_main);
linearLayoutManager = new LinearLayoutManager(this);//不设置方向默认是垂直
mainData.rvMain.setLayoutManager(linearLayoutManager);
userInfo = new ArrayList<>();//初始化的操作放在set之前
setUserInfo();
/**
* 这里用TestListItemAdapter是因为adapter里面需要写不同类型的item或者需要自己单独去设置某控件的值
* 如果是相同类型的，比如下面的gridLayoutManager就直接用BaseRecyleAdapter
* 这里的BR是dataBinding自动生成的，我们在布局中写好变量，用“BR.变量名”就能得到
*/
Map map = new HashMap<>();
map.put(R.layout.item_main, BR.info);
map.put(R.layout.item_main_diverse, BR.info2);
mainAdapter = new TestListItemAdapter(userInfo, map);
mainData.rvMain.setAdapter(mainAdapter);
/**
* 加载Grid类型的，这里设置3行
*/
gridLayoutManager = new GridLayoutManager(this, 3);
mainData.rvMainGrid.setLayoutManager(gridLayoutManager);
Map gridMap = new HashMap<>();
gridMap.put(R.layout.item_main_grid, BR.gridinfo);
mainGridAdapter = new BaseRecyleAdapter(userInfo, gridMap);
mainData.rvMainGrid.setAdapter(mainGridAdapter);
}
private void setUserInfo() {
for (int i = 0; i < 5; i++) {
UserInfo userInfo = new UserInfo();
userInfo.setTitle("以梦为马，诗酒趁年华" + i);
userInfo.setName(" ");
userInfo.setCover("http://jyts-public-oss.longruncloud.com/images/4ee98d67ccf5e5d33db6eba5046e1e289eb8d787f7888aab69280e169b4556c5.jpg");
userInfo.setAge("年龄:" + String.valueOf(i));
this.userInfo.add(userInfo);
}
}
}
注释已经很详细，就不赘述了，其中用到了实体类是自己写的，如果是服务端给的接口也是一样用的。Bean代码贴出来：
public class UserInfo {
private String cover;
private String title;
private String name;
private String age;
public String getCover() {
return cover;
}
public void setCover(String cover) {
this.cover = cover;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
}
public class TestListItemAdapter extends BaseRecyleAdapter {
public TestListItemAdapter(List data, Map hashMap) {
super(data, hashMap);
}
/**
* 如果有值不是从bean类里面获取的，需要自己去设置的话就重写此方法
* @param holder
* @param position
*/
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
super.onBindViewHolder(holder, position);
int i = position + 1;
String text = i >= 10 ? String.valueOf(i) : String.valueOf("0" + i);
holder.dataBinding.setVariable(BR.itemNum, text);//这里就是设置前面的序号
}
/**
* 编写规则,返回相应布局,比如这里是第四个item加载其他布局
*
* @param position
* @return
*/
@Override
public int getItemViewType(int position) {
if (position == 3)
return R.layout.item_main_diverse;
else
return R.layout.item_main;
}
}
public class ImagBindingUtils {
@BindingAdapter("imgurl")
public static void bindingImage(ImageView imageView, String url) {
Glide.with(imageView.getContext()).load(url).into(imageView);//用的glide加载，在build.gradle中添加依赖就能使用
}
}
public class ListenerBookRankAdapter extends BaseRecyleAdapter implements BaseRecyleAdapter.OnRecycleitemOnClic {
private List booksBeanDes;
public ListenerBookRankAdapter(List data, Map hashMap) {
super(data, hashMap);
this.booksBeanDes = (List) data;
setOnRecycleitemOnClic(this);//2.设置item点击，Base中已写好
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
super.onBindViewHolder(holder, position);
int i = position + 1;
String text = i >= 10 ? String.valueOf(i) : String.valueOf("0" + i);
holder.dataBinding.setVariable(BR.itemtestnum, text);
}
@Override
public void onItemClic(View view, int position) {//3.重写方法
int id = booksBeanDes.get(position).getBook().getId();
Intent intent = new Intent();
intent.putExtra("ID", id);
intent.setClass(view.getContext(), BookRankDetailsActivity.class);
view.getContext().startActivity(intent);
}
}