只需将代码放入onCreate()方法中

/* Like This*/

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.your_activity);

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    layoutManager = new LinearLayoutManager(YourActivity.this);
    recyclerView.setLayoutManager(layoutManager);
    recyclerView.setHasFixedSize(true);
    mAdapter = new YourAdapter(YourModelClassObject);
    recyclerView.setAdapter(mAdapter);
}

我也犯了同样的错误，我修复了它如果你像我一样在等待数据，使用改造或类似的东西

放在Oncreate之前

private ArtistArrayAdapter adapter;
private RecyclerView recyclerView;

把它们放在Oncreate中

 recyclerView = (RecyclerView) findViewById(R.id.cardList);
 recyclerView.setHasFixedSize(true);
 recyclerView.setLayoutManager(new LinearLayoutManager(this));
 adapter = new ArtistArrayAdapter( artists , R.layout.list_item ,getApplicationContext());
 recyclerView.setAdapter(adapter);

当你收到数据时放

adapter = new ArtistArrayAdapter( artists , R.layout.list_item ,getApplicationContext());
recyclerView.setAdapter(adapter);

现在进入ArtistArrayAdapter类，执行这个操作它会做的是如果数组为空或为空它会让GetItemCount返回0如果不是它会让它成为艺术家数组的大小

@Override
public int getItemCount() {

    int a ;

    if(artists != null && !artists.isEmpty()) {

        a = artists.size();
    }
    else {

        a = 0;

     }

   return a;
}

检查是否错过了在适配器中调用此方法

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

ArtistArrayAdapter adapter = new ArtistArrayAdapter(this, artists);
recyclerView = (RecyclerView) findViewById(R.id.cardList);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

只要用这个替换上面的代码，它就应该工作了。你所做的错误是在调用布局管理器之前调用了setAdapter(适配器)。

我有这个错误，我试着修复了一段时间，直到我找到解决方案。

我做了一个私有方法buildRecyclerView，我调用它两次，第一次在onCreateView，然后在我的回调(其中我从API获取数据)。这是我的方法buildRecyclerView在我的片段:

private void buildRecyclerView(View v) {
        mRecyclerView = v.findViewById(R.id.recycler_view_loan);
        mLayoutManager = new LinearLayoutManager(getActivity());
        ((LinearLayoutManager) mLayoutManager).setOrientation(LinearLayoutManager.VERTICAL);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mAdapter = new LoanAdapter(mExampleList);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.setAdapter(mAdapter);
}

此外，我必须修改我的适配器中的get-Item-Count方法，因为On - On - create - view列表是空的，它通过一个错误。所以，我的get-Item-Count如下所示:

@Override
    public int getItemCount() {
        try {
            return mLoanList.size();
        } catch (Exception ex){return 0;}

    }

解决方法是在底部设置初始化的空列表和适配器，并在获取结果时调用notifyDataSetChanged。

    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
    recyclerviewItems.setLayoutManager(linearLayoutManager);
    someAdapter = new SomeAdapter(getContext(),feedList);
    recyclerviewItems.setAdapter(someAdapter);