Question

我是使用recycviewview的新手，将它与cardview一起使用，有人可以告诉我如何初始化它吗？

我看到我必须以某种方式将它放在onCreateView中，而不是在ViewCreated中，我的代码：

  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                         @Nullable Bundle savedInstanceState) {

return inflater.inflate(R.layout.fragment_genres, container, false);

和回收者的代码我在Activity上使用的是什么，但现在我想在片段中触发它

  recyclerView = (RecyclerView) getActivity().findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);
    layoutManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(layoutManager);

数据痕迹：

JSON>get>DataModel>Adapter>Recycler>CardView

当我在onCreatedView中使用它时，LogCat说：

  java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference

Answer 1

就像这样

let z: (Int, String) = largestNum(interestingNumbers)

Answer 2

试试这个

  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
View v = inflater.inflate(R.layout.fragment_genres, container, false);
recyclerView = (RecyclerView) getActivity().findViewById(R.id.recyclerView); recyclerView.setHasFixedSize(true); layoutManager = new LinearLayoutManager(getActivity()); recyclerView.setLayoutManager(layoutManager);
    return v;

Answer 3

在这里，我成功地将Recyclerview集成到一个名为MainFragment的片段中 item click for recycler view 主活动中片段的初始化不存在。用它来引用片段

public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super. onCreate(savedInstanceState);
setContentView(R . layout . activity_main);
if(savedInstanceState == null ) {
getSupportFragmentManager() . beginTransaction()
.replace(R . id . container, MainFragment . newInstance())
.commit();

Fragment中的RecyclerView初始化

3 个答案: