onBindViewHolder只为我在recyclerview中单击的第一个元素调用

Question

我有一个片段，其中有recyclerview，并为其设置了适配器。如果我点击第一个添加到购物车，然后点击第二个。之后，当片段重新启动时，只有“第一次添加到购物车”的状态才会更改。同样地，如果我在重启后单击recyclerview中的第一个添加到购物车元素，则只有第二个添加到购物车的状态被更改。我想调用从0到适配器中最后一个元素的onBindViewHolder位置。在ViewHolder类中，有一个Add_to_cart change监听器。

public void onBindViewHolder(@NonNull final MilkAdapter1.ViewHolder holder, int position) {
    // I need to call this method for all elements in recyclerview whenever restarted 
    if (c != null && c.moveToFirst()) {
        do {
            for (int i = 0; i < list.size(); i++) {
                if (name.equals(holder.product_name.getText().toString())) {  // if present just update the AddToCart status
                   // if add_to_cart element is present in sqlite Database, just update its status
                    holder.textView.setVisibility(View.GONE); // this will change the Add to Cart status
                    holder.linearLayout.setVisibility(View.VISIBLE);
                    holder.digit.setText(quantit + "");
                }
            }
        } while (c.moveToNext());
        c.close();
    }

}

抱歉，我不能上传图片到我的应用程序，因为较少的声誉。

Answer 1

假设您正在将所选项目存储在ArrayList中（如果您不这样做，我建议您这样做），解决方案是：

public void onBindViewHolder(@NonNull final MilkAdapter1.ViewHolder holder, int position) {
    // I need to call this method for all elements in recyclerview whenever restarted 
    if (c != null && c.moveToFirst()) {
        do {
            if (nameArrayList.contains(holder.product_name.getText().toString())) {  // if present just update the AddToCart status
                   // if add_to_cart element is present in sqlite Database just update its status
                holder.textView.setVisibility(View.GONE); // this will change the Add to Cart status
                holder.linearLayout.setVisibility(View.VISIBLE);
                holder.digit.setText(quantit + "");
            }
        } while (c.moveToNext());
        c.close();
    }
}

正如Sachin Soma所指出的，您不需要为循环调用，因为列表中的每个项目都会调用一次onBindViewHolder。

Answer 2

你可以实现这个使用位置不要使用for循环...

@Override
    public int getItemCount() {
        return list.size();
    }


public void onBindViewHolder(@NonNull final MilkAdapter1.ViewHolder holder, int position) {
    // I need to call this method for all elements in recyclerview whenever restarted 
    if (c != null && c.moveToFirst()) {
        do {

                if (name.equals(holder.product_name.getText().toString())) {  // if present just update the AddToCart status
                   // if add_to_cart element is present in sqlite Database just update its status
                    holder.textView.setVisibility(View.GONE); // this will change the Add to Cart status
                    holder.linearLayout.setVisibility(View.VISIBLE);
                    holder.digit.setText(quantit + "");

            }
        } while (c.moveToNext());
        c.close();
    }

}