recylerview的适配器中的方法getItemcount

Question

这里的代码属于类

public class AdapterOrderShop extends 
RecyclerView.Adapter<AdapterOrderShop.HolderOrderShop>
implements Filterable {
private Context context;
public ArrayList<ModelOrderShop> orderShopArrayList,filterList;
private FilterOrderShop filter;
public AdapterOrderShop(Context context, ArrayList<ModelOrderShop> orderShopArrayList) {
this.context = context;
this.orderShopArrayList = orderShopArrayList;
this.filterList=orderShopArrayList;
}
@Override
public int getItemCount() {
return orderShopArrayList.size();
} 

尝试对null调用虚拟方法"int java.util.ArrayList.size(("目标参考

Answer 1

您应该在adapter构造函数中初始化您的列表，问题就解决了。未初始化的列表返回导致此错误发生的null。您可以在adapter中创建构造函数，然后从activity或fragment传递到adapter中声明的列表。如果您从activity或fragment传递context，则您具有与下面相同的构造函数，但如果您没有传递context，则从构造函数中移除Context参数。

public YourAdapterName(Context mCtx, List<YourModelClassName> taskList) {
this.mCtx = mCtx;
this.orderShopArrayList= taskList;
}