java回收视图。setAdapter（安卓x.recyclerview.widget.recyclerview适配器
尝试在recycler视图内使用recycler视图第一个适配器工作正常，但第二个适配器从未运行 厌倦了一遍又一遍地修理它，什么都不管用。。。。帮助 第二个recycler视图是从Firebase检索数据
接收到来自firebase的数据，但从未设置为所需的文本视图
活动
public class ScheduleOrder extends AppCompatActivity implements IFirebaseLoadListener {
DeviceSession deviceSession;
UserSession userSession;
String Device_Id="",User_Id="";
MyItemAdapter myItemAdapter;
IFirebaseLoadListener iFirebaseLoadListener;
List<String> Name;
List<ItemData>itemData;
ItemData itemData1;
RecyclerView my_recycler_view;
DatabaseReference myData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_schedule_order);
itemData1=new ItemData();
deviceSession = new DeviceSession(getApplicationContext());
Device_Id = deviceSession.getDeviceDetails();
userSession = new UserSession(getApplicationContext());
final HashMap<String, String> user = userSession.getUserDetails();
User_Id = user.get(UserSession.User_Id);
FloatingActionButton myFab = (FloatingActionButton)findViewById(R.id.schedule_add);
myFab.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(),Schedule_Order.class);
startActivity(i);
finish();
}
});
myData=FirebaseDatabase.getInstance().getReference("Cart_Schedule"+"/"+Device_Id);
iFirebaseLoadListener=this;
my_recycler_view=findViewById(R.id.my_recyclr_view);
my_recycler_view.setHasFixedSize(true);
// my_recycler_view1.setHasFixedSize(true);
my_recycler_view.setLayoutManager(new LinearLayoutManager(this));
// my_recycler_view1.setLayoutManager(new LinearLayoutManager(this));
getFirebaseData();
}
private void getFirebaseData() {
myData.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
List<ItemGroup>itemGroups=new ArrayList<>();
Name=new ArrayList<>();
for(DataSnapshot groupSnapShot:dataSnapshot.getChildren()){
ItemGroup itemGroup=new ItemGroup();
itemGroup.setD_Time(groupSnapShot.child("d_Time").getValue(true).toString());
itemGroup.setF_Amount(groupSnapShot.child("f_Amount").getValue(true).toString());
for(DataSnapshot newdatasnap:groupSnapShot.child("listItem").getChildren()){
itemData1.setA_Item_name(newdatasnap.child("a_Item_name").getValue().toString());
itemData1.setB_Quantity(newdatasnap.child("b_Quantity").getValue().toString());
itemData1.setC_Price(newdatasnap.child("b_Quantity").getValue().toString());
Name.add(newdatasnap.child("a_Item_name").getValue().toString());
Name.add(newdatasnap.child("c_Price").getValue().toString());
Name.add(newdatasnap.child("b_Quantity").getValue().toString());
Log.d("JADOO", "onDataChange: ??? "+itemData1.getA_Item_name());
Log.d("JADOO", "onDataChange: ??? "+itemData1.getB_Quantity());
Log.d("JADOO", "onDataChange: ??? "+itemData1.getC_Price());
Log.d("JADOO", "onDataChange: ??? "+Name);}
Log.d("JADOO", "onDataChange: ====================================================");
itemGroups.add(itemGroup);
Name.clear();
}
iFirebaseLoadListener.onFirebaseLoadSuccess(itemGroups);
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
iFirebaseLoadListener.onFirebaseLoadFailed(databaseError.getMessage());
}
});
}
@Override
public void onFirebaseLoadSuccess(List<ItemGroup> itemGroupList) {
Log.d("JADOO", "onDataChange: Setting Adapter");
MyItemGroupAdapter adapter = new MyItemGroupAdapter(ScheduleOrder.this,itemGroupList,itemData1);
my_recycler_view.setAdapter(adapter);
}
@Override
public void onFirebaseLoadFailed(String message) {
}
}
第一个适配器Java文件
public class MyItemGroupAdapter extends RecyclerView.Adapter<MyItemGroupAdapter.MyViewHolder> {
private Context context;
private List<ItemGroup>dataList;
private ItemData name;
public MyItemGroupAdapter(Context context, List<ItemGroup> dataList,ItemData data) {
this.context = context;
this.dataList = dataList;
this.name=data;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View itemView=LayoutInflater.from(context).inflate(R.layout.tempcartlayout,viewGroup,false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull final MyViewHolder myViewHolder, int i) {
MyItemAdapter itemListAdapter = new MyItemAdapter(context,name);
myViewHolder.timee.setText(dataList.get(i).getD_Time());
myViewHolder.cost.setText(dataList.get(i).getF_Amount());
Log.d("JADOO", "onDataChange: IN MY ITEM GRP ADAPTER "+name.getA_Item_name());
myViewHolder.recycler_view_item_list.setHasFixedSize(true);
myViewHolder.recycler_view_item_list.setLayoutManager(new CustomLinearLayoutManager(context,LinearLayoutManager.VERTICAL,false));
myViewHolder.recycler_view_item_list.setAdapter(itemListAdapter);
myViewHolder.recycler_view_item_list.setNestedScrollingEnabled(false);
myViewHolder.can.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(context, "Button More : "+myViewHolder.timee.getText()+" -- "+myViewHolder.cost.getText(), Toast.LENGTH_SHORT).show();
}
});
}
@Override
public int getItemCount() {
return (dataList != null ? dataList.size() : 0);
}
public class MyViewHolder extends RecyclerView.ViewHolder {
TextView timee,cost;
Button can;
RecyclerView recycler_view_item_list;
public MyViewHolder(@NonNull View itemView) {
super(itemView);
timee=itemView.findViewById(R.id.reorder_time);
cost=itemView.findViewById(R.id.reorder_cost);
can=itemView.findViewById(R.id.button);
Log.d("JADOO", "onDataChange: VIEW HOLDER ");
recycler_view_item_list=itemView.findViewById(R.id.schedulecart);
}}}
第二个适配器文件
private Context context;
private ItemData name123;
public MyItemAdapter(Context context, ItemData Item_Name) {
this.context = context;
this.name123=Item_Name;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View itemView= LayoutInflater.from(context).inflate(R.layout.cart_list_layout,viewGroup,false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, final int i) {
Log.d("JADOO", "onBindViewHolder: IN MY ITEM ADAPTER");
ItemData itemData=new ItemData();
myViewHolder.m_name.setText(itemData.getA_Item_name());
myViewHolder.m_cost.setText(itemData.getC_Price());
myViewHolder.m_quant.setText(itemData.getB_Quantity());
}
@Override
public int getItemCount() {
return 0;
}
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView m_name,m_quant,m_cost;
IItemClickListener iItemClickListener;
public void setiItemClickListener(IItemClickListener iItemClickListener){
this.iItemClickListener=iItemClickListener;
}
public MyViewHolder(@NonNull View itemView) {
super(itemView);
m_name=itemView.findViewById(R.id.tv_menu_name1);
m_quant=itemView.findViewById(R.id.quantity);
m_cost=itemView.findViewById(R.id.amount);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View view) {
iItemClickListener.onItemClickListener(view,getAdapterPosition());
}}}
错误
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.food.pilo, PID: 28457
java.lang.NullPointerException: Attempt to invoke virtual method 'void 安卓x.recyclerview.widget.RecyclerView.setAdapter(安卓x.recyclerview.widget.RecyclerView$Adapter)' on a null object reference
at com.food.pilo.ScheduleOrder.onFirebaseLoadSuccess(ScheduleOrder.java:161)
at com.food.pilo.ScheduleOrder$2.onDataChange(ScheduleOrder.java:143)
at com.google.firebase.database.Query$1.onDataChange(com.google.firebase:firebase-database@@16.0.4:183)
at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@16.0.4:75)
at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@16.0.4:63)
at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@16.0.4:55)
at 安卓.os.Handler.handleCallback(Handler.java:873)
at 安卓.os.Handler.dispatchMessage(Handler.java:99)
at 安卓.os.Looper.loop(Looper.java:214)
at 安卓.app.ActivityThread.main(ActivityThread.java:7156)
at java.lang.reflect.Method.invoke(Native Method)
at com.安卓.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
at com.安卓.internal.os.ZygoteInit.main(ZygoteInit.java:975)```
# 1 楼答案
# 2 楼答案
我认为
my_recycler_view=findViewById(R.id.my_recyclr_view);或者findViewById(R.id.schedulecart);返回空值请检查这些行