android - Android 如何在单击 ListView 项目时隐藏和显示 ListView 中的项目

Question

嘿，我正在使用和 android ListView，当我单击 ListView 项目时，我想显示一些项目，同时在同一个 ListView 中添加其他项目。我的意思是当我点击一个项目时，一些图像会显示在同一行。当我单击另一个项目时，以前的图像会消失，而我只剩下新行中的图像，请帮助这是我的代码

inventoryList.setAdapter(mAdapter);
    inventoryList.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                long arg3) {
            // TODO Auto-generated method stub                  
            LinearLayout lButtons;

            // Hides all items in the listView adapter  
            for (int i = 0; i < inventoryList.getAdapter().getCount(); i++) {


                   View v1 = inventoryList.getChildAt(i);  
                   lButtons = (LinearLayout) v1.findViewById(R.id.layout_update_buttons);
                   lButtons.setVisibility(View.GONE);


            }

            //Display images of currently clicked item
            lButtons = (LinearLayout) arg1.findViewById(R.id.layout_update_buttons);
            lButtons.setVisibility(View.VISIBLE);

        }

    });

它目前在这个特定的行中给了我一个 java.lang.nullPointerException

lButtons = (LinearLayout) v1.findViewById(R.id.layout_update_buttons);

Answer 1

这是我在一些帮助后得到的答案

inventoryList.setAdapter(mAdapter);
    inventoryList.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                long arg3) {
            // TODO Auto-generated method stub                  
            LinearLayout lButtons;

            // Hides all items in the listView adapter  
            for (int i = 0; i < inventoryList.getAdapter().getCount(); i++) {


                   View v1 = inventoryList.getChildAt(i);  
                   if(v1 != null){
                   lButtons = (LinearLayout) v1.findViewById(R.id.layout_update_buttons);
                   lButtons.setVisibility(View.GONE);
                   }


            }

            //Display images of currently clicked item
            lButtons = (LinearLayout) arg1.findViewById(R.id.layout_update_buttons);
            lButtons.setVisibility(View.VISIBLE);

        }

    });