我实际上获取了数据并用 print 打印了它。但是当我添加到列表中时,它给出了空对象异常。我该如何解决这个问题?我收到错误,因为我正在创建一个空对象。我不明白为什么。,我该怎么做才能解决?
myRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()){
Mac mac = new Mac();
mac.setMackodu(ds.getValue(Mac.class).getMackodu());
mac.setTakimlar(ds.getValue(Mac.class).getTakimlar());
mac.setTahmin(ds.getValue(Mac.class).getTahmin());
System.out.println("macss " + mac.getMackodu());
System.out.println("macss " + mac.getTakimlar());
System.out.println("macss " + mac.getTahmin());
macList.add(mac);
}
myRecyclerAdapter = new MyRecyclerAdapter(getContext(),macList);
recyclerView.setAdapter(myRecyclerAdapter);
myRecyclerAdapter.notifyDataSetChanged();
}
public class Mac{
private String macKodu;
private String takimlar;
private String tahmin;
public Mac() {
}
public Mac(String macKodu, String takimlar, String tahmin) {
this.macKodu = macKodu;
this.takimlar = takimlar;
this.tahmin = tahmin;
}
public String getMacKodu() {
return macKodu;
}
public void setMacKodu(String macKodu) {
this.macKodu = macKodu;
}
public String getTakimlar() {
return takimlar;
}
public void setTakimlar(String takimlar) {
this.takimlar = takimlar;
}
public String getTahmin() {
return tahmin;
}
public void setTahmin(String tahmin) {
this.tahmin = tahmin;
}
最佳答案
放入这两行
myRecyclerAdapter = new MyRecyclerAdapter(getContext(),macList);
recyclerView.setAdapter(myRecyclerAdapter);
出
myRef.addValueEventListener
关于java - 我正在从 Firebase 拍摄数据,但无法将其添加到列表中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/53132346/