我正在接受收银员申请。使用回收站视图显示订单队列。但是，我在类之间传递ArrayList值时遇到麻烦，而且在更新回收器视图时遇到了麻烦。在这种情况下，我不会对回收站有一个很大的看法，因此性能不会成为问题，但是一种优化的方法将不胜感激。我只是不知道如何解决这个问题。
[我试图在MainActivty类中创建一个set方法，我也尝试了放置多余的意图，但是我不相信我完全理解多余的放置。
MainActivity类别：
public class MainActivity extends AppCompatActivity implements MyRecyclerViewAdapter.ItemClickListener { private RecyclerView recyclerView; private RecyclerView.Adapter mAdapter; private RecyclerView.LayoutManager layoutManager; public ArrayList<String> orderList = new ArrayList<>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Toolbar toolbar = findViewById(R.id.toolbar); setSupportActionBar(toolbar); // set up the RecyclerView recyclerView = findViewById(R.id.recyle_view_activity); recyclerView.setLayoutManager(new LinearLayoutManager(this)); mAdapter = new MyRecyclerViewAdapter(this, orderList); ((MyRecyclerViewAdapter) mAdapter).setClickListener(this); recyclerView.addItemDecoration(new DividerItemDecoration(this, DividerItemDecoration.VERTICAL)); recyclerView.setAdapter(mAdapter); } //This is the set method I attempted: public void setOrderAdd(ArrayList<String> data){ if (data != null){ mAdapter = new MyRecyclerViewAdapter(this,data); //Error refrences here } } }其他班级：
public class regularCoffee extends AppCompatActivity implements AdapterView.OnItemSelectedListener, Serializable { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_regular_coffee); Toolbar toolbar = findViewById(R.id.toolbar); setSupportActionBar(toolbar); addToOrder(); } public void addToOrder(){ //Reg Addons: final CheckBox leaveRoomReg = findViewById(R.id.leave_room_reg); final CheckBox cinnamonReg = findViewById(R.id.cinnamon_reg); final CheckBox chocolateSyrupReg = findViewById(R.id.chocolate_syrup_reg); final CheckBox whiteChocolateSyrupReg = findViewById(R.id.white_chocolate_syrup_reg); final CheckBox caramelReg = findViewById(R.id.caramelReg); final CheckBox hazelnutReg = findViewById(R.id.hazel_nut_reg); final CheckBox[] RegCoffeeAddOns = {leaveRoomReg,cinnamonReg,chocolateSyrupReg,whiteChocolateSyrupReg,caramelReg,hazelnutReg}; //Decaf Addons: final Button leaveRoomDecaf = findViewById(R.id.leave_room_decaf); final Button cinnamonDecaf = findViewById(R.id.cinnamon_decaf); final Button chocolateSyrupDecaf = findViewById(R.id.chocolate_syrup_decaf); final Button whiteChocolateDecaf = findViewById(R.id.white_chocolate_syrup_decaf); final Button caramelDecaf = findViewById(R.id.caramel_decaf); final Button hazelnutDecaf = findViewById(R.id.hazel_nut_decaf); final Button[] DecafCoffeeAddOns = {leaveRoomDecaf,cinnamonDecaf,caramelDecaf,chocolateSyrupDecaf,whiteChocolateDecaf,hazelnutDecaf}; Button addToOrderButton = findViewById(R.id.addToOrderReg); addToOrderButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { MainActivity addToOrderArea = new MainActivity(); String forOrder; ArrayList<String> tempArray = new ArrayList<>(); if (regCoffeeQuantity > 0){ forOrder = "Regular Coffee (x" + regCoffeeQuantity + ") \n "; for (int i = 0; i < RegCoffeeAddOns.length; i++){ if (RegCoffeeAddOns[i].isChecked()){ forOrder = forOrder + "| " + RegCoffeeAddOns[i].getText().toString() + " "; System.out.println(forOrder); } } addToOrderArea.setOrderAdd(tempArray); //Error refrences here } } }); }RecyclerView适配器：
package com.example.holygroundsapplication; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import androidx.recyclerview.widget.RecyclerView; import java.util.List; public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> { private List<String> mData; private LayoutInflater mInflater; private ItemClickListener mClickListener; // data is passed into the constructor MyRecyclerViewAdapter(Context context, List<String> data) { this.mInflater = LayoutInflater.from(context); //Error refrences here. this.mData = data; } // inflates the row layout from xml when needed @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View view = mInflater.inflate(R.layout.recyclerview_row, parent, false); return new ViewHolder(view); } // binds the data to the TextView in each row @Override public void onBindViewHolder(ViewHolder holder, int position) { String animal = mData.get(position); holder.myTextView.setText(animal); } // total number of rows @Override public int getItemCount() { return mData.size(); } // stores and recycles views as they are scrolled off screen public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { TextView myTextView; ViewHolder(View itemView) { super(itemView); myTextView = itemView.findViewById(R.id.tvAnimalName); itemView.setOnClickListener(this); } @Override public void onClick(View view) { if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition()); } } // convenience method for getting data at click position String getItem(int id) { return mData.get(id); } // allows clicks events to be caught void setClickListener(MainActivity itemClickListener) { this.mClickListener = itemClickListener; } // parent activity will implement this method to respond to click events public interface ItemClickListener { void onItemClick(View view, int position); } }这是错误：
java.lang.IllegalStateException: System services not available to Activities before onCreate()
at android.app.Activity.getSystemService(Activity.java:5774)
at android.view.LayoutInflater.from(LayoutInflater.java:233)
at com.example.holygroundsapplication.MyRecyclerViewAdapter.<init>(MyRecyclerViewAdapter.java:21)
at com.example.holygroundsapplication.MainActivity.setOrderAdd(MainActivity.java:89)
at com.example.holygroundsapplication.regularCoffee$8.onClick(regularCoffee.java:262)
...
我正在接受收银员申请。使用回收站视图显示订单队列。但是，我在类之间传递ArrayList值时遇到麻烦，而且在更新回收站时也遇到麻烦...
在onClick功能中，您具有
我认为您在逻辑上需要替换