Question

我正在使用firebase并将值传递给listview

将值传递给listview我使用以下

requestList request = requestSnapshot.getValue(requestList.class);

我还需要存储记录的密钥，但它不包含在getValue调用中。

我决定为密钥编写自己的setter并将其添加到requestList类

我正在手动设置密钥

request.setrequestKey(requestSnapshot.getKey());

当我在添加请求后直接打印请求值时，我得到了正确的值

 Log.i("Chat", request.getRequestTitle()+": "+request.getRequestDescription()+"    "+request.getrequestKey());

返回此

RequestTitle: RequestDescription    -KK4yufLTSScKHzvZtM4

然后我想在像这样的onclicklistener中使用request.getrequestkey

 messagesView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {
        requestList o = (requestList) messagesView.getItemAtPosition(position);

        String requestKey = o.getrequestKey();

        Toast.makeText(getActivity(),requestKey,Toast.LENGTH_SHORT).show();
    }
});

但是requestKey为null，但requestTitle和requestDescription存在且正确

我无法理解为什么班级不保留价值

任何人都可以帮忙吗

这是我的requestList类

public class requestList {

    String RequestTitle;
    String RequestDescription;
    String requestKey;

    //DataSnapshot requestSnapshot;


    public requestList() {
    }

    public requestList(String RequestTitle, String RequestDescription) {
        this.RequestTitle = RequestTitle;
        this.RequestDescription = RequestDescription;
        //this.key = key;

        //this.requestSnapshot = requestSnapshot;
    }

    public String getRequestTitle() {
        return RequestTitle;
    }

    public String getrequestKey() {
        return requestKey;
    }

    public String getRequestDescription() {
        return RequestDescription;
    }


    public void setrequestKey(String requestKey) {
        this.requestKey = requestKey;
    }
}

我现在根据评论请求包括完整的课程

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

        myView = inflater.inflate(R.layout.activity_request, container, false);

        final ListView messagesView = (ListView) myView.findViewById(listView);


        test mApp = (test) getActivity().getApplication();

        //test mApp = ((getView())getApplicationContext());
        String UID = mApp.getUID();

        DatabaseReference ref = FirebaseDatabase.getInstance().getReference("users/" + UID + "/Requests" );

        ref.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot snapshot) {
                for (DataSnapshot requestSnapshot: snapshot.getChildren()) {
                    //requestList request = requestSnapshot.getValue(requestList.class);
                    requestList request = requestSnapshot.getValue(requestList.class);
                    request.setRequestKey(requestSnapshot.getKey());
                    Log.i("Chat", request.getRequestTitle()+": "+request.getRequestDescription()+"    "+request.getRequestKey());

                    }
            }

            @Override
            public void onCancelled(DatabaseError firebaseError) {
                Log.e("Chat", "The read failed: " + firebaseError.getMessage());
            }
        });



        ListAdapter mAdapter = new  FirebaseListAdapter<requestList>(getActivity(), requestList.class, android.R.layout.two_line_list_item, ref) {
            @Override
            protected void populateView(View view, requestList requestListItem, int position) {
                ((TextView)view.findViewById(android.R.id.text1)).setText(requestListItem.getRequestTitle());
                ((TextView)view.findViewById(android.R.id.text2)).setText(requestListItem.getRequestDescription());

            }


        };


        messagesView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {

                requestList o = (requestList) messagesView.getItemAtPosition(position);

                String requestKey = o.getRequestKey();

                Toast.makeText(getActivity(),requestKey,Toast.LENGTH_SHORT).show();
            }
        });


        messagesView.setAdapter(mAdapter);


        return myView;



    }
}

我现在包括数据库值

{
  "AccountID" : "ABC123",
  "Created" : "today",
  "Name" : "value",
  "Requests" : {
    "-KK4yufLTSScKHzvZtM4" : {
      "RequestDescription" : "Request Description 3",
      "RequestItems" : {
        "-KK4yv8qnh7YHe7WuJ8B" : {
          "Description" : "Item Descriptiopn",
          "Title" : "Item Title"
        },
        "-KK4yv8rPsnJr824rAON" : {
          "Description" : "Item Descriptiopn",
          "Title" : "Item Title"
        },
        "-KK4yv8s3ivK7Mfx166H" : {
          "Description" : "Item Descriptiopn",
          "Title" : "Item Title"
        },
        "-KK4yv8tKoM2sV1gyOkz" : {
          "Description" : "Item Descriptiopn",
          "Title" : "Item Title"
        }
      },
      "RequestTitle" : "value"
    }
  }
}

Answer 1

由于您使用的是FirebaseUI，因此您无需自行跟踪密钥。您可以使用adapter.getRef(...).getKey()轻松获取它：

messagesView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
  public void onItemClick(AdapterView<?> parent, View view,
                            int position, long id) {
    requestList o = (requestList) messagesView.getItemAtPosition(position);

    String requestKey = adapter.getRef(position).getKey();

    Toast.makeText(getActivity(),requestKey,Toast.LENGTH_SHORT).show();
  }
});

getValue setter不存储值

1 个答案: