java - 从另一个类获取按钮调用
问题描述
我有两个班OrderAdapter.java
OrderActivity.java
。类OrderAdapter.java
中有一个按钮,当我单击它时,必须更改类中的文本视图OrderActivity.java
。当我运行应用程序时,textview 会更改一次,因为这行是有意的:
textView_order_price.setText(adapter.totalAmount + "");
但是当我再次按下按钮时,它应该再次更改文本,但事实并非如此。你们能帮帮我吗?
订单活动.java
package com.nfc.netvision;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import java.util.ArrayList;
public class OrderActivity extends AppCompatActivity {
RecyclerView recyclerView;
TextView textView_order_price;
ArrayList<ModelOrder> orderArrayList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_order);
recyclerView = findViewById(R.id.recyclerview_order_scroll);
textView_order_price = findViewById(R.id.textView_order_price);
orderArrayList = new ArrayList<>();
orderArrayList.add(new ModelOrder(R.drawable.coke, "Coka Cola", "Eine Cola hält dich wach und schmeckt dazu.", "3",0));
orderArrayList.add(new ModelOrder(R.drawable.fastfood, "Pommes", "Fritten für die Titten.", "5",0));
orderArrayList.add(new ModelOrder(R.drawable.water, "Wasser", "Still und sanft, so mag ich es.", "5",0));
orderArrayList.add(new ModelOrder(R.drawable.burger, "Burger", "Ach mir fällt nichts ein.", "10",0));
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
RecyclerView.LayoutManager recLiLayoutManager = layoutManager;
recyclerView.setLayoutManager(recLiLayoutManager);
OrderAdapter adapter = new OrderAdapter(this, orderArrayList);
recyclerView.setAdapter(adapter);
textView_order_price.setText(adapter.totalAmount + "");
System.out.println(adapter.totalAmount + "TOASBTORT");
}
}
OrderAdapter.java
package com.nfc.netvision;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.google.firestore.v1.StructuredQuery;
import java.util.ArrayList;
public class OrderAdapter extends RecyclerView.Adapter<OrderAdapter.ViewHolder> {
public int totalAmount;
private Context mContext;
private ArrayList<ModelOrder> nList;
OrderAdapter(Context context, ArrayList<ModelOrder> list) {
mContext = context;
nList = list;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(mContext);
View view = layoutInflater.inflate(R.layout.recyclerview_order_items, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, int position) {
final ModelOrder orderItem = nList.get(position);
ImageView image = holder.item_image;
final TextView name, place, price;
name = holder.item_name;
place = holder.item_place;
price = holder.item_price;
image.setImageResource(orderItem.getImage());
name.setText(orderItem.getName());
place.setText(orderItem.getPlace());
price.setText(orderItem.getPrice());
holder.order_item_minus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(orderItem.getCounter() > 0) {
orderItem.setCounter(orderItem.getCounter()-1);
holder.order_item_count.setText("" + orderItem.getCounter());
calculatePrice(Integer.parseInt((String) price.getText()), false);
}
}
});
holder.order_item_plus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(orderItem.getCounter() < 9) {
orderItem.setCounter(orderItem.getCounter() + 1);
holder.order_item_count.setText("" + orderItem.getCounter());
calculatePrice(Integer.parseInt((String) price.getText()), true);
}
}
});
}
@Override
public int getItemCount() {
return nList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
ImageView item_image;
TextView item_name, item_place, item_price,order_item_minus,order_item_count, order_item_plus;
public ViewHolder(@NonNull View itemView) {
super(itemView);
item_image = itemView.findViewById(R.id.order_item_image);
item_name = itemView.findViewById(R.id.order_item_name);
item_place = itemView.findViewById(R.id.order_item_place);
item_price = itemView.findViewById(R.id.order_item_price);
order_item_minus = itemView.findViewById(R.id.order_item_minus);
order_item_plus = itemView.findViewById(R.id.order_item_plus);
order_item_count = itemView.findViewById(R.id.order_item_count);
}
}
public void calculatePrice(int pPrice, boolean pUpDown) {
if(pUpDown) {
totalAmount = totalAmount + pPrice;
}
else {
totalAmount = totalAmount - pPrice;
}
System.out.println(totalAmount);
}
}
解决方案
2种方法来解决您的问题:
第一种方式 - 非常简单 - 只需将您的 textView 从活动添加到构造函数适配器;
private TextView orderPrice;
OrderAdapter(Context context, ArrayList<ModelOrder> list,TextView orderPrice) {
mContext = context;
nList = list;
this.orderPrice = orderPrice;
}
public void calculatePrice(int pPrice, boolean pUpDown) {
if(pUpDown) {
totalAmount = totalAmount + pPrice;
}
else {
totalAmount = totalAmount - pPrice;
}
//here you add totalAmount to your textView in activity
orderPrice.setText(totalAmount.toString)
System.out.println(totalAmount);
}
2d 方式在您的适配器中创建接口并在您的活动中实现它;
//第一次在你的适配器中创建接口,如下所示:
public class OrderAdapter extends
RecyclerView.Adapter<OrderAdapter.ViewHolder> {
public int totalAmount;
private Context mContext;
private ArrayList<ModelOrder> nList;
private TotalListener listener;
interface TotalListener{
void onTotalChanged(String result);
}
OrderAdapter(Context context, ArrayList<ModelOrder> list,TotalListener listener) {
mContext = context;
nList = list;
this.listener = listener;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(mContext);
View view = layoutInflater.inflate(R.layout.recyclerview_order_items, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, int position) {
final ModelOrder orderItem = nList.get(position);
ImageView image = holder.item_image;
final TextView name, place, price;
name = holder.item_name;
place = holder.item_place;
price = holder.item_price;
image.setImageResource(orderItem.getImage());
name.setText(orderItem.getName());
place.setText(orderItem.getPlace());
price.setText(orderItem.getPrice());
holder.order_item_minus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(orderItem.getCounter() > 0) {
orderItem.setCounter(orderItem.getCounter()-1);
holder.order_item_count.setText("" + orderItem.getCounter());
calculatePrice(Integer.parseInt((String) price.getText()), false);
}
}
});
holder.order_item_plus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(orderItem.getCounter() < 9) {
orderItem.setCounter(orderItem.getCounter() + 1);
holder.order_item_count.setText("" + orderItem.getCounter());
calculatePrice(Integer.parseInt((String) price.getText()), true);
}
}
});
}
@Override
public int getItemCount() {
return nList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
ImageView item_image;
TextView item_name, item_place, item_price,order_item_minus,order_item_count, order_item_plus;
public ViewHolder(@NonNull View itemView) {
super(itemView);
item_image = itemView.findViewById(R.id.order_item_image);
item_name = itemView.findViewById(R.id.order_item_name);
item_place = itemView.findViewById(R.id.order_item_place);
item_price = itemView.findViewById(R.id.order_item_price);
order_item_minus = itemView.findViewById(R.id.order_item_minus);
order_item_plus = itemView.findViewById(R.id.order_item_plus);
order_item_count = itemView.findViewById(R.id.order_item_count);
}
}
public void calculatePrice(int pPrice, boolean pUpDown) {
if(pUpDown) {
totalAmount = totalAmount + pPrice;
}
else {
totalAmount = totalAmount - pPrice;
}
//this is callback to your activity
listener.onTotalChanged(totalAmount.toString)
System.out.println(totalAmount);
}
}
这是您更新的活动
public class OrderActivity extends AppCompatActivity impelemts OrderAdapter.TotalListener {
RecyclerView recyclerView;
TextView textView_order_price;
ArrayList<ModelOrder> orderArrayList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_order);
recyclerView = findViewById(R.id.recyclerview_order_scroll);
textView_order_price = findViewById(R.id.textView_order_price);
orderArrayList = new ArrayList<>();
orderArrayList.add(new ModelOrder(R.drawable.coke, "Coka Cola", "Eine Cola hält dich wach und schmeckt dazu.", "3",0));
orderArrayList.add(new ModelOrder(R.drawable.fastfood, "Pommes", "Fritten für die Titten.", "5",0));
orderArrayList.add(new ModelOrder(R.drawable.water, "Wasser", "Still und sanft, so mag ich es.", "5",0));
orderArrayList.add(new ModelOrder(R.drawable.burger, "Burger", "Ach mir fällt nichts ein.", "10",0));
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
RecyclerView.LayoutManager recLiLayoutManager = layoutManager;
recyclerView.setLayoutManager(recLiLayoutManager);
OrderAdapter adapter = new OrderAdapter(this, orderArrayList,this);
recyclerView.setAdapter(adapter);
textView_order_price.setText(adapter.totalAmount + "");
System.out.println(adapter.totalAmount + "TOASBTORT");
}
@Override
public void onTotalChanged(String result) {
textView_order_price.setText(result);
}
}
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