Question

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        listView=container.findViewById(R.id.listview);
       // View view= inflater.inflate(R.layout.fragment_home_page, container, false);
        View v = getActivity().getLayoutInflater().inflate(R.layout.fragment_home_page,null);
        final HomePageListAdapter homePageListAdapter=new HomePageListAdapter(container.getContext(),productName,sku,type,profile,getLayoutInflater());
        listView.setAdapter(homePageListAdapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
               Toast.makeText(getContext(),productName[position],Toast.LENGTH_SHORT).show();
            }
        });

        return v;
    }

java.lang.NullPointerException：尝试调用虚拟方法'void android.widget.ListView.setOnItemClickListener（android.widget.AdapterView $ OnItemClickListener）' 在com.example.webcreta.ui.home.Home.HomePage.HomePageFragment.onCreateView（HomePageFragment.java:42）上的空对象引用上

Answer 1

先膨胀视图然后初始化

尝试以下代码：

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment

       // View view= inflater.inflate(R.layout.fragment_home_page, container, false);
        View v = getActivity().getLayoutInflater().inflate(R.layout.fragment_home_page,null);
       listView=v.findViewById(R.id.listview);
        final HomePageListAdapter homePageListAdapter=new HomePageListAdapter(container.getContext(),productName,sku,type,profile,getLayoutInflater());
        listView.setAdapter(homePageListAdapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
               Toast.makeText(getContext(),productName[position],Toast.LENGTH_SHORT).show();
            }
        });

        return v;
    }

Answer 2

尝试此代码

View view;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.fragment_home_page, container, false);
    listView = view.findViewById(R.id.listview);    
    final HomePageListAdapter homePageListAdapter=new HomePageListAdapter(container.getContext(),productName,sku,type,profile,getLayoutInflater());
    listView.setAdapter(homePageListAdapter);
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Toast.makeText(getContext(),productName[position],Toast.LENGTH_SHORT).show();
        }
    });
    return view;
}

希望对您有帮助

如何在此代码中解决此Null Exception错误？

2 个答案: