Question

让我们说我正在写这个数据的课程：

data in firebase

    reliclistener = mydb.child("relics").addValueEventListener(new ValueEventListener() {

            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {


                for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
                    Log.d("inside",childSnapshot.getValue().toString());


                    relics.put(childSnapshot.getKey(), childSnapshot.getValue(Relic.class));
                    Log.d("insiderelic",relics.get(childSnapshot.getKey()).getDrop().getName()); //not workin
                }
    }
});

有一个遗物地图采用遗物类对象。

childSnapshot.getKey()).getDrop().getName()为空

这是Relic类：

public class Relic {
  public Double latitude;
  public Double longitude;
  public Drop mydrop;

  public Relic() {}

  public Double getLatitude() {
    return latitude;
  }
  public Double getLongitude() {
    return longitude;
  }

  public Drop getDrop() {
    return mydrop;
  }

  public static class Drop {

    String name;
    int count;

    Drop() {

    } 

    public String getName() {
      return name;
    }
    public int getCount() {
      return count;
    }
  }
}

Log.d里面的结果：

{latitude = 0，经度= 0，drop = {name = test，count = 1}}

{latitude = 40.8923772，经度= 29.3805392，drop = {name = qwew，count = 20}}

另一个问题是，如果数据结构如下，我该怎么办？

drop
   0
    name:test
    count:3
   1
    name:somethng
    count:4

Answer 1

重新定义您的遗物类：

public class Relic {
    private Double latitude;
    private Double longitude;
    private Drop drop;

    public Double getLatitude() {
        return latitude;
    }

    public void setLatitude(Double latitude) {
        this.latitude = latitude;
    }

    public Double getLongitude() {
        return longitude;
    }

    public void setLongitude(Double longitude) {
        this.longitude = longitude;
    }

    public Drop getDrop() {
        return drop;
    }

    public void setDrop(Drop drop) {
        this.drop = drop;
    }
}

你的掉落课程：

public class Drop {

    private String name;
    private int count;

    public String getName() {
        return name;
    }

    public int getCount() {
        return count;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setCount(int count) {
        this.count = count;
    }
}

现在你可以做到：

 for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
             Relic relic = childSnapshot.getValue(Relic.class);

  }

如果你想要一个滴剂列表（第二个问题），你可以像这样定义你的遗物类：

public class Relic {
    private List<Drop> drop;
   ...
   }

嵌套数据firebase的嵌套类

1 个答案: