如何增加对Android的观点持有者变量的值？ [英] How to increment a value on view holder variables in android?

问题描述

我有一个 viewholder 在我的Andr​​oid应用程序，我想在一个文本框设置增加值。我试图像下面，

活动

  @覆盖
公共查看getView（INT位置，查看convertView，ViewGroup中父）{
    如果（convertView == NULL）{
        持有人=新的持有人（）;
        LayoutInflater充气=（LayoutInflater）this.context
                .getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
        convertView = inflater.inflate（R.layout.menu_list_item，NULL）;

        holder.textViewItemName =（TextView中）convertView.findViewById（R.id.textViewItemName）;
        holder.textViewPrice =（TextView中）convertView.findViewById（R.id.textViewPrice）;
        holder.imageView =（ImageView的）convertView.findViewById（R.id.imageViewItem）;
        holder.buttonPlus =（ButtonRectangle）convertView.findViewById（R.id.buttonPlus）;
        holder.cartQtyTextView =（TextView中）convertView.findViewById（R.id.textViewCartQty）;
        holder.buttonMinus =（ButtonRectangle）convertView.findViewById（R.id.buttonMinus）;
        convertView.setTag（保持器）;
    } 其他 {
        支架=（座）convertView.getTag（）;
    }
    最终的菜单项的listItem = objects.get（位置）;
    holder.textViewItemName.setText（listItem.getItemName（））;
    holder.textViewPrice.setText（$.concat（将String.valueOf（listItem.getItemPrice（））））;

    //检查和放大器;组
    如果（holder.buttonPlus！= NULL）{
        holder.buttonPlus.setOnClickListener（新View.OnClickListener（）{
            @覆盖
            公共无效的onClick（视图v）{

                如果（holder.cartQtyTextView！= NULL）{
                    如果（holder.inc＆GT; = 0）{
                        holder.cartQtyTextView.setText（将String.valueOf（holder.inc ++））;
                    }
                }
            }
        }）;
    }
    holder.buttonPlus.setBackgroundColor（Color.WHITE）;
    holder.buttonPlus.setTextColor（Color.parseColor（＃333333））;

    //检查和放大器;组
    如果（holder.buttonMinus！= NULL）{
        holder.buttonMinus.setOnClickListener（新View.OnClickListener（）{
            @覆盖
            公共无效的onClick（视图v）{
                如果（holder.inc＆GT; = 0）{
                    holder.cartQtyTextView.setText（将String.valueOf（holder.inc--））;
                }
            }
        }）;
    }
    holder.buttonMinus.setBackgroundColor（Color.WHITE）;
    holder.buttonMinus.setTextColor（Color.parseColor（＃333333））;

    返回convertView;

}
 

架

 类持有人{
    ButtonRectangle buttonPlus;
    ButtonRectangle buttonMinus;
    TextView的cartQtyTextView;
    TextView的textViewItemName;
    TextView的textViewPrice;
    ImageView的ImageView的;
    INT INC;
}
 

但这递增随机。我如何解决这个问题？

解决方案

 ＆GT;但是，这是递增随机
 

这是因为viewholder可能属于不同的顺序线。

示例

• 在开始viewholder＃1属于订单行＃1 INC = 2
• 如果您向下滚动列表框订单行＃1变为不可见和订单行＃27变为可见。
• 现在，订单行＃27重用viewholder＃1和INC = 2

如何解决这一问题：

您需要存储的数据公司，条款ArticleID，数量，单价，articlename，......

这是objectmodell

 最终订单项订单项=（订单项）objects.get（位置）;
 ...
 orderItem.inc ++;
 

另请参见<一个href="http://stackoverflow.com/search?q=listview+random">http://stackoverflow.com/search?q=listview+random

I have a viewholder in my Android app and I tried to set an incremented value on a textfield. I tried it like following,

Activity

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    if (convertView == null) {
        holder = new Holder();
        LayoutInflater inflater = (LayoutInflater) this.context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = inflater.inflate(R.layout.menu_list_item, null);

        holder.textViewItemName = (TextView) convertView.findViewById(R.id.textViewItemName);
        holder.textViewPrice = (TextView) convertView.findViewById(R.id.textViewPrice);
        holder.imageView = (ImageView) convertView.findViewById(R.id.imageViewItem);
        holder.buttonPlus = (ButtonRectangle) convertView.findViewById(R.id.buttonPlus);
        holder.cartQtyTextView = (TextView) convertView.findViewById(R.id.textViewCartQty);
        holder.buttonMinus = (ButtonRectangle) convertView.findViewById(R.id.buttonMinus);
        convertView.setTag(holder);
    } else {
        holder = (Holder) convertView.getTag();
    }
    final MenuItem listItem = objects.get(position);
    holder.textViewItemName.setText(listItem.getItemName());
    holder.textViewPrice.setText("$ ".concat(String.valueOf(listItem.getItemPrice())));

    // Check & Set
    if (holder.buttonPlus != null) {
        holder.buttonPlus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                if (holder.cartQtyTextView != null) {
                    if (holder.inc >= 0) {
                        holder.cartQtyTextView.setText(String.valueOf(holder.inc++));
                    }
                }
            }
        });
    }
    holder.buttonPlus.setBackgroundColor(Color.WHITE);
    holder.buttonPlus.setTextColor(Color.parseColor("#333333"));

    // Check & Set
    if (holder.buttonMinus != null) {
        holder.buttonMinus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (holder.inc >= 0) {
                    holder.cartQtyTextView.setText(String.valueOf(holder.inc--));
                }
            }
        });
    }
    holder.buttonMinus.setBackgroundColor(Color.WHITE);
    holder.buttonMinus.setTextColor(Color.parseColor("#333333"));

    return convertView;

}

Holder

class Holder {
    ButtonRectangle buttonPlus;
    ButtonRectangle buttonMinus;
    TextView cartQtyTextView;
    TextView textViewItemName;
    TextView textViewPrice;
    ImageView imageView;
    int inc;
}

But this is incrementing randomly. How may I fix this?

解决方案

 > But this is incrementing randomly

that is because the viewholder may belong to different order-lines.

Example

• in the beginning viewholder#1 belongs to orderline #1 with inc=2
• if you scroll down the listbox orderline #1 becomes invisible and orderline #27 becomes visible. .
• now orderline #27 is reusing viewholder#1 and with inc=2

how to fix this:

you need an objectmodell that store the data inc, articleid, quantity, unitprice, articlename, ......

 final OrderItem orderItem = (OrderItem) objects.get(position);
 ...
 orderItem.inc++;

See also http://stackoverflow.com/search?q=listview+random

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