java.lang.IndexOutOfBoundsException:当我尝试从recyclerview列表中删除项时
当我试图从列表中删除最后一项时,它会给我IndexOutOfBound错误,它只发生在列表中的最后一项上 这是我的密码java.lang.IndexOutOfBoundsException:当我尝试从recyclerview列表中删除项时,java,android,android-recyclerview,indexoutofboundsexception,Java,Android,Android Recyclerview,Indexoutofboundsexception,当我试图从列表中删除最后一项时,它会给我IndexOutOfBound错误,它只发生在列表中的最后一项上 这是我的密码 public class CartAdapter extends RecyclerView.Adapter<CartViewHolder> { private List<Order> listData = new ArrayList<>(); private CartActivity cartActivity; pri
public class CartAdapter extends RecyclerView.Adapter<CartViewHolder> {
private List<Order> listData = new ArrayList<>();
private CartActivity cartActivity;
private int total;
public CartAdapter(List<Order> listData, CartActivity cartActivity) {
this.listData = listData;
this.cartActivity = cartActivity;
}
@NonNull
@Override
public CartViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(cartActivity);
View itemView = inflater.inflate(R.layout.cart_layout, viewGroup, false);
return new CartViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull final CartViewHolder cartViewHolder, @SuppressLint("RecyclerView") final int i) {
cartViewHolder.counterButton.setNumber(listData.get(i).getQuantity());
cartViewHolder.counterButton.setOnValueChangeListener(new ElegantNumberButton.OnValueChangeListener() {
@Override
public void onValueChange(ElegantNumberButton view, int oldValue, int newValue) {
total = 0;
Order order = listData.get(i);
order.setQuantity(String.valueOf(newValue));
new Database(cartActivity).updateCart(order);
calculate();
}
});
cartViewHolder.txt_price.setText(listData.get(i).getPrice());
cartViewHolder.txt_cart_name.setText(listData.get(i).getFoodName());
cartViewHolder.removeItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
listData.remove(i);
notifyItemRemoved(i);
notifyItemRangeChanged(i, listData.size());
Order order = listData.get(i);
new Database(cartActivity).clearItem(order);
calculate();
}
});
}
private void calculate(){
for (Order orders: listData){
total += Integer.parseInt(orders.getPrice()) * Integer.parseInt(orders.getQuantity());
Log.d("GDGDGD", String.valueOf(total));
}
int cgst = (total * 5)/100;
total += cgst;
Locale locale = new Locale("en","IN");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
cartActivity.txtTotalPrice.setText(fmt.format(total));
}
}
上面的代码是来自recyclerview的代码片段,它是从数据库中获取的项,并创建了列表 问题是这一行:Order=listData.geti
您先删除项目,然后尝试获取订单
listData.remove(i); // remove item from listData: it will have zero items if earlier, listData had one item
...
Order order = listData.get(i); // get ith order: will crash if listData's size is 0
放置listData.removei;在函数结束时,将解决该问题
像这样:
cartViewHolder.removeItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
notifyItemRemoved(i);
notifyItemRangeChanged(i, listData.size());
Order order = listData.get(i);
new Database(cartActivity).clearItem(order);
listData.remove(i);
calculate();
}
});
private void calculate(){
total = 0;
for (Order orders: listData){
total += Integer.parseInt(orders.getPrice()) * Integer.parseInt(orders.getQuantity());
Log.d("GDGDGD", String.valueOf(total));
}
int cgst = (total * 5)/100;
total += cgst;
Locale locale = new Locale("en","IN");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
cartActivity.txtTotalPrice.setText(fmt.format(total));
}
cartViewHolder.counterButton.setOnValueChangeListener(new ElegantNumberButton.OnValueChangeListener() {
@Override
public void onValueChange(ElegantNumberButton view, int oldValue, int newValue) {
Order order = listData.get(i);
order.setQuantity(String.valueOf(newValue));
new Database(cartActivity).updateCart(order);
calculate();
}
})
编辑:
计算中还有一个问题。您必须将变量total重新指定为零
像这样:
cartViewHolder.removeItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
notifyItemRemoved(i);
notifyItemRangeChanged(i, listData.size());
Order order = listData.get(i);
new Database(cartActivity).clearItem(order);
listData.remove(i);
calculate();
}
});
private void calculate(){
total = 0;
for (Order orders: listData){
total += Integer.parseInt(orders.getPrice()) * Integer.parseInt(orders.getQuantity());
Log.d("GDGDGD", String.valueOf(total));
}
int cgst = (total * 5)/100;
total += cgst;
Locale locale = new Locale("en","IN");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
cartActivity.txtTotalPrice.setText(fmt.format(total));
}
cartViewHolder.counterButton.setOnValueChangeListener(new ElegantNumberButton.OnValueChangeListener() {
@Override
public void onValueChange(ElegantNumberButton view, int oldValue, int newValue) {
Order order = listData.get(i);
order.setQuantity(String.valueOf(newValue));
new Database(cartActivity).updateCart(order);
calculate();
}
})
并去掉total=0;分配像这样:
cartViewHolder.removeItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
notifyItemRemoved(i);
notifyItemRangeChanged(i, listData.size());
Order order = listData.get(i);
new Database(cartActivity).clearItem(order);
listData.remove(i);
calculate();
}
});
private void calculate(){
total = 0;
for (Order orders: listData){
total += Integer.parseInt(orders.getPrice()) * Integer.parseInt(orders.getQuantity());
Log.d("GDGDGD", String.valueOf(total));
}
int cgst = (total * 5)/100;
total += cgst;
Locale locale = new Locale("en","IN");
NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);
cartActivity.txtTotalPrice.setText(fmt.format(total));
}
cartViewHolder.counterButton.setOnValueChangeListener(new ElegantNumberButton.OnValueChangeListener() {
@Override
public void onValueChange(ElegantNumberButton view, int oldValue, int newValue) {
Order order = listData.get(i);
order.setQuantity(String.valueOf(newValue));
new Database(cartActivity).updateCart(order);
calculate();
}
})
这似乎是一个学习自己调试的好机会。您是否已检查是否删除了以前项目的正确项目?当代码到达remove调用时,它是否仍然包含项?项目索引是否可能从1开始索引,而不是像列表一样从0开始索引?所有能帮你找到答案的东西。非常感谢@MartinZeitler指出这一点。现在,这个问题已经解决了。谢谢你们的帮助,现在当我移除物品时,总价值会增加。