此 Firebase 查询（orderbyKey）无法显示任何内容

Question

我正在尝试从 child("REPORTS") 获取数据，其中 datasnapshot.getRef 与从 getIntent 传递的密钥相同，没有显示，我无法判断代码语法有什么问题

Intent i = getIntent();
final String key = i.getExtras().getString("firekey");

Query queryRef = mDatabase.child("REPORTS").equalTo(key).orderByKey();
queryRef.addChildEventListener(new ChildEventListener() {
  public void onChildAdded(DataSnapshot dataSnapshot, String s) {
    Log.d( "Post", "data");
    Map<String, Object> newPost = (Map<String, Object>) dataSnapshot.getValue();
    if (newPost != null) {
      reportSingle = new FoodItem(newPost.get("MEAL_TITLE").toString().trim(),
      newPost.get("DESCRIPTION").toString().trim(),
      newPost.get("MEAL_INGREDIENTS").toString().trim(),

Answer 1

您似乎正在尝试加载单个报告。在这种情况下，您需要：

DatabaseReference reportRef = mDatabase.child("REPORTS").child(key);
reportRef.addValueEventListener(new ValueEventListener() {
  public void onDataChanged(DataSnapshot dataSnapshot) {
    Log.d( "Post", "data");
    if (dataSnapshot.exists()) {
      reportSingle = new FoodItem(
        dataSnapshot.child("MEAL_TITLE").getValue(String.class).trim(),
        dataSnapshot.child("DESCRIPTION").getValue(String.class).trim(),
        dataSnapshot.child("MEAL_INGREDIENTS").getValue(String.class).trim(),

此 Firebase 查询（orderbyKey）无法显示任何内容

This Firebase query(orderbyKey) cannot display anything

android

firebase

firebase-realtime-database