嗨,大家好我試着去檢索火力數據,只有先從字母C和按字母排序,但是當我運行程序它什麼都不做,我可以檢索所有房間,沒有問題火力點的數據。這裏是我的代碼請幫助。獲取與Android和排序孩子
public class RoomsActivity extends AppCompatActivity
{
private Button add_room;
private EditText room_name;
private ListView listView;
private ArrayAdapter<String> arrayAdapter;
private ArrayList<String> list_of_rooms = new ArrayList<>();
private String name;
private DatabaseReference root = FirebaseDatabase.getInstance().getReference().getRoot();
private String user_name;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_rooms);
name = getIntent().getExtras().get("user_name").toString();
getWindow().setBackgroundDrawableResource(R.drawable.back2);
add_room = (Button) findViewById(R.id.btn_add_room);
room_name = (EditText) findViewById(R.id.room_name_edittext);
listView = (ListView) findViewById(R.id.listView);
arrayAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,list_of_rooms);
listView.setAdapter(arrayAdapter);
add_room.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Map<String,Object> map = new HashMap<String, Object>();
map.put(room_name.getText().toString(),"");
root.updateChildren(map);
}
});
root.child("room_name").startAt("C").orderByKey().addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Set<String> set = new HashSet<String>();
Iterator i = dataSnapshot.getChildren().iterator();
while (i.hasNext()){
set.add(((DataSnapshot)i.next()).getKey());
}
list_of_rooms.clear();
list_of_rooms.addAll(set);
arrayAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Intent intent = new Intent(getApplicationContext(),Chat_Room.class);
intent.putExtra("room_name",((TextView)view).getText().toString());
intent.putExtra("user_name",name);
startActivity(intent);
}
});
}
}
我的數據庫
private DatabaseReference root = FirebaseDatabase.getInstance().getReference().getRoot();
當II得到的所有數據被檢索
root.orderByKey().addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Set<String> set = new HashSet<String>();
Iterator i = dataSnapshot.getChildren().iterator();
while (i.hasNext()){
set.add(((DataSnapshot)i.next()).getKey());
}
list_of_rooms.clear();
list_of_rooms.addAll(set);
arrayAdapter.notifyDataSetChanged();
}
根我用[火力文檔] [1]作爲參考,但不能得到它的工作
你能附上您的火力地堡數據的截圖? –
@boonyakipitak截圖添加 –