回收站视图在 Fragment 中不起作用

Posted 2023-04-15

【中文标题】回收站视图在 Fragment 中不起作用

【英文标题】：Recycler View Does not works in Fragment

【发布时间】：2021-04-16 13:21:16

【问题描述】：

我一直在制作一个在Fragment 中使用recyclerView 的应用程序，但recyclerView 的内容尚未显示。它显示：

 'No adapter attached; skipping layout'.

特色助手类：

public class FeaturedHelperClass 

    int image;
    String title;

    public FeaturedHelperClass(int image, String title) 
        this.image = image;
        this.title = title;
    

    public int getImage() 
        return image;
    

    public String getTitle() 
        return title;
    

片段：

RecyclerView.Adapter adapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
        featuredRecycle = inflater.inflate(R.layout.fragment_dashboard, container, false).findViewById(R.id.explore_recycle);
        recycle();
        return inflater.inflate(R.layout.fragment_dashboard, container, false);
    

private void recycle()

        featuredRecycle.setHasFixedSize(true);
        featuredRecycle.setLayoutManager(new LinearLayoutManager(getActivity()));

        ArrayList<FeaturedHelperClass> featuredLocations = new ArrayList<>();

        featuredLocations.add(new FeaturedHelperClass(R.drawable.mcdonald, "Mcdonald's"));
        featuredLocations.add(new FeaturedHelperClass(R.drawable.kfc, "KFC"));
        featuredLocations.add(new FeaturedHelperClass(R.drawable.starbucks, "Starbucks"));

        adapter = new FeaturedAdapter(featuredLocations);
        featuredRecycle.setAdapter(adapter);
    

【问题讨论】：

您给定的数据和代码是不够的。发布您的 fragment_dashboard.xml。并解释为什么你的特点回收和你的片段分开膨胀？

【参考方案1】：

未附加视图膨胀回收器视图适配器后出现'No adapter attached; skipping layout'. 的原因。

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
        featuredRecycle = inflater.inflate(R.layout.fragment_dashboard, container, false).findViewById(R.id.explore_recycle);
        recycle();
        return inflater.inflate(R.layout.fragment_dashboard, container, false);
    

因为 recycle() 方法会在视图膨胀之前执行。

我们可以把它改成

//inflate the view and return
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
         View view = inflater.inflate(R.layout.fragment_dashboard, container, false);
         return view;
   

//this callback is just after once the view get inflated in the screen
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) 
             featuredRecycle = view.findViewById(R.id.explore_recycle);
             recycle();
   

现在我们得到featuredRecycle 视图并执行recycle() 逻辑，将绘制recycler。

【参考方案2】：

您的通货膨胀逻辑似乎有缺陷，请尝试在您的 onCreateView 中更改以下内容

featuredRecycle = inflater.inflate(R.layout.fragment_dashboard, container, false).findViewById(R.id.explore_recycle);
recycle();
return inflater.inflate(R.layout.fragment_dashboard, container, false);

进入

View view = inflater.inflate(R.layout.fragment_dashboard, container, false);
featuredRecycle = view.findViewById(R.id.explore_recycle);
recycle();
return view;

【参考方案3】：

以下内容对您有用，但它不是延迟片段中视图膨胀的好方法。由于您在返回视图之前执行了一些任务，因此会延迟视图膨胀。

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
         View view = inflater.inflate(R.layout.fragment_dashboard, container, false);
         featuredRecycle = view.findViewById(R.id.explore_recycle);
         recycle()
         return view;
   

执行以下操作将是最佳方法，

//inflate the view and return
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
         View view = inflater.inflate(R.layout.fragment_dashboard, container, false);
         return view;
   

//this callback is just after the view inflation, you set your ui here
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) 
             featuredRecycle = view.findViewById(R.id.explore_recycle);
             recycle()
   

【讨论】：

代替getView()，我们可以使用视图本身。基本上，两者都只会给出膨胀的视图。