如何修复不兼容的类型：无法将片段转换为上下文。

huangapple
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英文:

How to fix incompatible types: fragment cannot be converted to Context

问题

这是出现问题的那一行代码：

  1. FirestoreList.setLayoutManager(new LinearLayoutManager(this));// this is the line that is giving me the error

要解决这个问题，你可以尝试将 this 更改为 requireContext()，如下所示：

  1. FirestoreList.setLayoutManager(new LinearLayoutManager(requireContext()));

这样应该可以解决你的错误。

英文:

i am trying to view items from my database and i have written everything to retrieve that and display it in an activity page. but this one line of code gives an error that doesn't allow the app to run:

here is my detailed code:

  1. public class HomeFragment extends Fragment {
  3.     private String name;
  4.     private String location;
  5.     private String country;
  6.     private String address;
  8.     public HomeFragment() {
  10.     }
  12.     public HomeFragment(String name, String location, String country, String address) {
  13.         this.name = name;
  14.         this.location = location;
  15.         this.country = country;
  16.         this.address = address;
  19.     }
  21.     public String getName() {
  22.         return name;
  23.     }
  25.     public void setName(String name) {
  26.         this.name = name;
  27.     }
  29.     public String getLocation() {
  30.         return location;
  31.     }
  33.     public void setLocation(String location) {
  34.         this.location = location;
  35.     }
  37.     public String getCountry() {
  38.         return country;
  39.     }
  41.     public void setCountry(String country) {
  42.         this.country = country;
  43.     }
  45.     public String getAddress() {
  46.         return address;
  47.     }
  49.     public void setAddress(String address) {
  50.         this.address = address;
  51.     }
  54.     private FirebaseFirestore firebaseFirestore;
  55.     private RecyclerView FirestoreList;
  57.     private FirestoreRecyclerAdapter adapter;
  58.     @Override
  59.     public View onCreateView(LayoutInflater inflater, ViewGroup container,
  60.                              Bundle savedInstanceState) {
  61.         firebaseFirestore = FirebaseFirestore.getInstance();
  62.        FirestoreList = FirestoreList.findViewById(R.id.firestore_list);
  64.         //query
  65.         Query q = firebaseFirestore.collection("Shops");
  67.         //recycle options
  68.         FirestoreRecyclerOptions<ShopModel> options = new FirestoreRecyclerOptions.Builder<ShopModel>().setQuery(q, ShopModel.class).build();
  70.          adapter = new FirestoreRecyclerAdapter<ShopModel, ShopViewHolder>(options) {
  71.             @NonNull
  72.             @Override
  73.             public ShopViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
  74.                 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_home,parent,false);
  75.                 return new ShopViewHolder(view);
  76.             }
  78.             @Override
  79.             protected void onBindViewHolder(@NonNull ShopViewHolder holder, int position, @NonNull ShopModel model) {
  80.                 holder.list_name.setText(model.getName());
  81.                 holder.list_country.setText(model.getName());
  82.                 holder.list_location.setText(model.getName());
  83.                 holder.list_address.setText(model.getName());
  84.             }
  85.         };
  86.         FirestoreList.setHasFixedSize(true);
  88.         FirestoreList.setLayoutManager(new LinearLayoutManager(this));// this is the line that is giving me the error
  90.         FirestoreList.setAdapter(adapter);
  94.         return inflater.inflate(R.layout.fragment_home, container, false);
  96.     }
  99.     private class ShopViewHolder extends RecyclerView.ViewHolder {
  100.         private TextView list_name;
  101.         private TextView list_country;
  102.         private TextView list_location;
  103.         private TextView list_address;
  104.         public ShopViewHolder(@NonNull View itemView) {
  105.             super(itemView);
  107.             list_name = itemView.findViewById(R.id.list_name);
  108.             list_country = itemView.findViewById(R.id.list_country);
  109.             list_location = itemView.findViewById(R.id.list_location);
  110.             list_address = itemView.findViewById(R.id.list_address);
  111.         }
  112.     }
  114.     @Override
  115.     public void onStart() {
  116.         super.onStart();
  117.         adapter.startListening();
  118.     }
  120.     @Override
  121.     public void onStop() {
  122.         super.onStop();
  123.         adapter.stopListening();
  124.     }
  125. }

this is the line where there is a problem at

FirestoreList.setLayoutManager(new LinearLayoutManager(this));// this is the line that is giving me the error

what can i do to resolve this?

答案1

得分: 2

你正在将你的片段传递给 LinearLayoutManager，而不是 Context。

所以你需要做的就是简单地替换这行代码

  1. FirestoreList.setLayoutManager(new LinearLayoutManager(this));

为

  1. FirestoreList.setLayoutManager(new LinearLayoutManager(requireContext()));
英文:

You are passing your fragment to LinearLayoutManager, not the Context

So what you need to do is simply replace this line

  1. FirestoreList.setLayoutManager(new LinearLayoutManager(this));

To

  1. FirestoreList.setLayoutManager(new LinearLayoutManager(requireContext()));

答案2

得分: 0

请创建一个名为FirestoreList的对象，并尝试将布局管理器设置为该对象：

  1. FirestoreList fsList = FirestoreList.findViewById(R.id.firestore_list);
  2. ...
  3. fsList.setLayoutManager(new LinearLayoutManager(this));
英文:

Can you please make an object for FirestoreList and try to set the LayoutManager to the object ?

  1. FirestoreList fsList = FirestoreList.findViewById(R.id.firestore_list);
  2. ...
  3. fsList.setLayoutManager(new LinearLayoutManager(this));

答案3

得分: 0

将这个语句更改为：

  1. View view = inflater.inflate(R.layout.fragment_home, container, false);
英文:

Change this statement :
return inflater.inflate(R.layout.fragment_home, container, false);

to:
View view = inflater.inflate(R.layout.fragment_home, container, false);

huangapple
  • 本文由 发表于 2020年8月2日 20:04:11
  • 转载请务必保留本文链接：https://go.coder-hub.com/63215770.html
  • android-studio
  • java
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