Firebase 数据库到 Spinner [代码清理帮助]

Question

正在尝试访问数据

我正在尝试将数据库的所有值存储到微调器中。最终结果应该是在微调器中显示所有值。代码以某种方式实现，但我觉得 spinnerData() 函数需要一些清理。

注意： 代码完全有效，但事实是它在 spinnerData() 中使用了太多的对象和太多的值传递，如果可以实现的话使用一些更简单的代码会很棒。

SymptomActivity.java

package com.example.nishantsikri.microdoctor;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.TextView;

import android.widget.Toast;

import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;


public class SymptomActivity extends AppCompatActivity {

private DatabaseReference mFirebaseDatabase, spinnerDatabase;
private FirebaseDatabase mFirebaseInstance;
Button button;
TextView textView;
Spinner spinner;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_symptom);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    button = (Button) findViewById(R.id.button8);
    textView = (TextView) findViewById(R.id.textView2);

    spinner = (Spinner) findViewById(R.id.spinner2);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
    FirebaseDatabase.getInstance().setPersistenceEnabled(true);


    // Write a message to the database
    mFirebaseInstance = FirebaseDatabase.getInstance();
    // store app title to 'app_title' node
    mFirebaseInstance.getReference("app_title").setValue("microDoctor");
    mFirebaseDatabase = mFirebaseInstance.getReference("symptomList");
    spinnerDatabase = mFirebaseInstance.getReference("symptomView");
    //mFirebaseDatabase.child("Headache").child("Some Value").setValue("Head");
    //mFirebaseDatabase.setValue("Headache");

    spinnerData();

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
        }
    });
}

private void readDataListener() {
    mFirebaseDatabase.child("Abdominal Cramps").child("Diarrhea").child("Vomiting").addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            Symptom symptom = dataSnapshot.getValue(Symptom.class);

            // Check for null
            if (symptom == null) {
                Log.e("Data", "Symptom data is null!");
                return;
            }

            Log.e("Symptom Data", "User data is changed!"+symptom.getDisease());

            // Display newly updated name and email
            textView.setText(symptom.symptom1+"\n"+symptom.symptom2+"\n"+symptom.symptom3+"\n"+symptom.disease+"\n"+dataSnapshot.getKey());
        }

        @Override
        public void onCancelled(DatabaseError error) {
            // Failed to read value
            Log.e("Error", "Failed to read user", error.toException());
        }
    });
}
private void spinnerData() {
    spinnerDatabase.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            Log.e("Spinner Data", "Spinner data is changed!");

            DataSnapshot data = dataSnapshot;
            Iterable<DataSnapshot> temp = data.getChildren();
            ArrayList<String> list = new ArrayList<>();
//                list.add(dataSnapshot.getValue().toString());
//                showDataInSpinner(list);
            for (DataSnapshot lists : temp){
                Log.d("ddd","Array List: "+lists.getValue().toString());
                list.add(lists.getValue().toString());
                textView.setText(lists.getValue().toString());
            }
            showDataInSpinner(list);

        }

        @Override
        public void onCancelled(DatabaseError error) {
            // Failed to read value
            Log.e("Error", "Failed to read user", error.toException());
        }
    });
}
public void showDataInSpinner(ArrayList<String> data) {
    ArrayAdapter<String> adapter = new ArrayAdapter<>(
            this, android.R.layout.simple_spinner_item, data
    ); //Create the Adapter to set the data
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); //Set the layout resource to create the drop down views.
    spinner.setAdapter(adapter); //Set the data to your spinner
}
}

Answer 1

您的代码没问题，但只有一件事需要删除。您不需要将 dataSnapshot 对象分配给新的 DataSnapshot 对象。您可以轻松地直接使用 dataSnapshot。因此，删除新创建的对象并在您的代码中仅使用 dataSnapshot。

Firebase 数据库到 Spinner [代码清理帮助]

Firebase database to Spinner [code cleaning help]

java

android

android-spinner

firebase

firebase-realtime-database