我有一个问题。2个按钮(+和-)有相同的计数器。例如,当我增加可乐时(比如说我们想要2杯可乐),我按了2次按钮,一切都正常,但是当我想要薯条时(除了2杯可乐外,还有1杯薯条),薯条的计数器增加到3,而它应该是1,因为我第一次点击了它。下面的图片显示了这个问题。
下面的xml和java类文件重建了你所看到的图像。也许你可以帮助我,我将非常感谢。
OrderActivity.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 java.util.ArrayList;
public class OrderActivity extends AppCompatActivity {
RecyclerView recyclerView;
ArrayList<ModelOrder> orderArrayList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_order);
recyclerView = findViewById(R.id.recyclerview_order_scroll);
orderArrayList = new ArrayList<>();
orderArrayList.add(new ModelOrder(R.drawable.coke, "Coka Cola", "Kaltes Getränml", "6"));
orderArrayList.add(new ModelOrder(R.drawable.fastfood, "Coka Cola", "Kaltes Getränml", "10"));
orderArrayList.add(new ModelOrder(R.drawable.water, "Coka Cola", "Kaltes Getränml", "20"));
orderArrayList.add(new ModelOrder(R.drawable.burger, "Coka Cola", "Kaltes Getränml", "30"));
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
RecyclerView.LayoutManager recLiLayoutManager = layoutManager;
recyclerView.setLayoutManager(recLiLayoutManager);
OrderAdapter adapter = new OrderAdapter(this, orderArrayList);
recyclerView.setAdapter(adapter);
}
}
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 androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
public class OrderAdapter extends RecyclerView.Adapter<OrderAdapter.ViewHolder> {
int value = 0; //Global
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) {
ModelOrder orderItem = nList.get(position);
ImageView image = holder.item_image;
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) {
value = value - 1;
holder.order_item_count.setText("" + value);
}
});
holder.order_item_plus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
value = value + 1;
holder.order_item_count.setText("" + value);
}
});
}
@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);
}
}
}
再生器查看器.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp">
<LinearLayout
android:weightSum="10"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/order_item_image"
android:layout_width="0dp"
android:layout_weight="4"
android:layout_height="128dp"
android:scaleType="centerCrop"
android:src="@drawable/coke"/>
<LinearLayout
android:layout_width="0dp"
android:layout_weight="4"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/order_item_name"
android:textSize="18sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:text="Name"/>
<TextView
android:id="@+id/order_item_place"
android:text="Description"
android:textSize="14sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
<TextView
android:id="@+id/order_item_price"
android:text="€ Preis"
android:layout_width="0dp"
android:layout_weight="2"
android:layout_gravity="center"
android:gravity="center"
android:textColor="#fff"
android:background="@drawable/capsule_order"
android:layout_height="30dp"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom">
<TextView
android:id="@+id/order_item_minus"
android:layout_width="28dp"
android:layout_height="28dp"
android:textSize="25dp"
android:layout_gravity="center"
android:gravity="center"
android:background="@drawable/capsule_order"
android:textColor="#fff"
android:textStyle="bold"
android:text="-"/>
<TextView
android:id="@+id/order_item_count"
android:layout_width="28dp"
android:layout_height="28dp"
android:textSize="25dp"
android:layout_gravity="center"
android:gravity="center"
android:textColor="#000"
android:textStyle="bold"
android:text="00"/>
<TextView
android:id="@+id/order_item_plus"
android:layout_width="28dp"
android:layout_height="28dp"
android:textSize="25dp"
android:layout_gravity="center"
android:gravity="center"
android:background="@drawable/capsule_order"
android:textColor="#fff"
android:textStyle="bold"
android:text="+"/>
</LinearLayout>
</LinearLayout>
</androidx.cardview.widget.CardView>
activity_order.xml
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="true"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerview_order_scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
</androidx.recyclerview.widget.RecyclerView>
</androidx.core.widget.NestedScrollView>
因为你总是访问 价值 中初始化的变量。
办法是加 价值 对你的 模型订单 并在模型中启动
然后接入
所以......每一行的情况都不一样。
OrderActivity.java / 用以下方法初始化每个模型 计数器=0
orderArrayList.add(new ModelOrder(R.drawable.coke, "Coka Cola", "Kaltes Getränml", "6",0));
orderArrayList.add(new ModelOrder(R.drawable.fastfood, "Coka Cola", "Kaltes Getränml", "10",0));
orderArrayList.add(new ModelOrder(R.drawable.water, "Coka Cola", "Kaltes Getränml", "20",0));
orderArrayList.add(new ModelOrder(R.drawable.burger, "Coka Cola", "Kaltes Getränml", "30",0));
OrderAdapter.java
去掉这一行
int value = 0; /全球
holder.order_item_minus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
orderItem.setCounter(orderItem.getCounter()-1);
holder.order_item_count.setText("" + orderItem.getCounter());
}
});
holder.order_item_plus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
orderItem.setCounter(orderItem.getCounter()+1);
holder.order_item_count.setText("" + orderItem.getCounter());
}
});
你要加 '数量' 属性,在你的 模型订单所以,增减值为 '数量' 在一个对象中根据加减按钮点击,并设置了 '数量' 在您的计数器文本视图中的值