相关疑难解决方法(0)

我在某处看到了这段代码并且想知道:何时以及为什么有人会做以下事情:

doSomething( (MyClass) null );

你有没有这样做过？你能分享一下你的经历吗？

我volley jar用来创建customListView下面是我用来实现的代码.我已经公开了.

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_inventory, container, false);

            button=(Button)rootView.findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    displayView(7);
                    //launchQRScanner(view);
                }
            });

            listView = (ListView) rootView.findViewById(R.id.list);
            adapter = new CustomListAdapter(getActivity(), inventoryList);
            listView.setAdapter(adapter);
            pDialog = new ProgressDialog(getActivity());
            // Showing progress dialog before making http request
            pDialog.setMessage("Loading...");
            pDialog.show();

            Log.d("Url: ",url);

            // Creating volley request obj
            JsonArrayRequest inventoryReq = new JsonArrayRequest(url,new Response.Listener<JSONArray>() {
                        @Override
                        public void onResponse(JSONArray response) …