欢迎使用firebase为valeter制作应用程序的人。我目前正在尝试进行一项名为添加工作的活动。活动的第一部分旨在找到您正在进行的护理。我希望通过搜索汽车的标志来做到这一点..
所以我创建了一个名为add_car的活动，其中我将汽车的详细信息添加到我的数据库中。这一切都有效，它使用注册作为主键然后有其他孩子，有助于区分车辆。因此，一旦添加了汽车，这就是我的数据库的外观
汽车 -----＆GT;
Kj65YHT（以制造注册为例） ---＆GT;
制造商福特
模特嘉年华
门2
enginesize 1600
reg Kj65YHT
数据添加和删除我的数据库罚款，但当我尝试搜索reg后，列表返回约7个空项目。这是我的代码
Add_Job活动
public class Add_Job extends AppCompatActivity implements View.OnClickListener {
private Button btnsubmit;
private EditText etreg;
private FirebaseDatabase db;
private DatabaseReference dbref;
private ListView mlv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add__job);
mlv = (ListView)findViewById(R.id.mlv);
btnsubmit = (Button)findViewById(R.id.btnsubmit);
btnsubmit.setOnClickListener(this);
etreg = (EditText)findViewById(R.id.etreg);
db = FirebaseDatabase.getInstance();
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.btnsubmit:
locateRegistration();
break;
}
}
private void locateRegistration(){
String reg = etreg.getText().toString().trim();
String Cars = "Cars";
dbref = db.getReference().child(Cars).child(reg);
HarropChildListener listner = new
HarropChildListener(mlv,Add_Job.this,dbref);
dbref.addChildEventListener(listner);
}
}
ChildEventListener类
public class HarropChildListener implements ChildEventListener {
private ListView mlv;
private static ArrayList<String> CAR_COLOUR;
private static ArrayList<String> AMOUNT_DOORS;
private static ArrayList<String> ENGINE_SIZE;
private static ArrayList<String> FUEL_TYPE;
private static ArrayList<String> CAR_MANUFACTURER;
private static ArrayList<String> CAR_MODEL;
private static ArrayList<String> CAR_REGISTRATION;
private Context mContext;
private dataListAdapter apkData;
private DatabaseReference ref;
public HarropChildListener(){
}
public HarropChildListener(ListView mlv,Context context, DatabaseReference dbref){
this.mlv = mlv;
this.mContext = context;
this.ref = dbref;
Log.i("Event","Started");
CAR_COLOUR = new ArrayList<>();
AMOUNT_DOORS = new ArrayList<>();
ENGINE_SIZE = new ArrayList<>();
FUEL_TYPE = new ArrayList<>();
CAR_MANUFACTURER = new ArrayList<>();
CAR_MODEL = new ArrayList<>();
CAR_REGISTRATION = new ArrayList<>();
}
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
if (dataSnapshot.exists()) {
Log.i("Event", "Added");
String a,b,c,d,e,f,g;
a = dataSnapshot.child("colour").getValue(String.class);
b = dataSnapshot.child("doors").getValue(String.class);
c = dataSnapshot.child("enginesize").getValue(String.class);
d = dataSnapshot.child("fuel").getValue(String.class);
e = dataSnapshot.child("manufacturer").getValue(String.class);
f = dataSnapshot.child("model").getValue(String.class);
g = dataSnapshot.child("reg").getValue(String.class);
CAR_COLOUR.add(a);
AMOUNT_DOORS.add(b);
ENGINE_SIZE.add(c);
FUEL_TYPE.add(d);
CAR_MANUFACTURER.add(e);
CAR_MODEL.add(f);
CAR_REGISTRATION.add(g);
final String[] colours = CAR_COLOUR.toArray(new String[CAR_COLOUR.size()]);
String[] doors = AMOUNT_DOORS.toArray(new String[AMOUNT_DOORS.size()]);
String[] engine = ENGINE_SIZE.toArray(new String[ENGINE_SIZE.size()]);
final String[] man = CAR_MANUFACTURER.toArray(new String[CAR_MANUFACTURER.size()]);
final String[] model = CAR_MODEL.toArray(new String[CAR_MODEL.size()]);
final String[] fuel = FUEL_TYPE.toArray(new String[FUEL_TYPE.size()]);
final String[] reg = CAR_REGISTRATION.toArray(new String[CAR_REGISTRATION.size()]);
apkData = new dataListAdapter(mContext, colours,fuel,man,model,reg,engine,doors);
mlv.setAdapter(apkData);
apkData.notifyDataSetChanged();
}
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
}
DatalistAdapter类
public class dataListAdapter extends BaseAdapter {
String[] Colour, FuelType;
String[] Manufacturer,Model,Reg,EngineSize ,Doors;
Context mContext;
TextView tv1,tv2,tv3,tv4,tv5,tv6,tv7;
public dataListAdapter() {
Colour = null;
FuelType = null;
Manufacturer = null;
Model = null;
Reg = null;
EngineSize = null;
Doors = null;
}
public dataListAdapter(Context c, String[] colour, String[] fuel, String[] manufacturer,String[]model,String[]reg,String[]engineSize, String[] doors) {
Colour = colour;
FuelType = fuel;
Manufacturer = manufacturer;
Model = model;
Reg = reg;
EngineSize = engineSize;
Doors = doors;
this.mContext = c;
}
public int getCount() {
// TODO Auto-generated method stub
return Reg.length;
}
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
final View row;
if (convertView == null) {
row = LayoutInflater.from(parent.getContext()).inflate(R.layout.custom, parent, false);
} else {
row = convertView;
}
tv1 = row.findViewById(R.id.tvcolour);
tv2 = row.findViewById(R.id.tvfuel);
tv3 = row.findViewById(R.id.tvmanufacture);
tv4 = row.findViewById(R.id.tvmodel);
tv5 = row.findViewById(R.id.tvreg);
tv6 = row.findViewById(R.id.tvengine);
tv7 = row.findViewById(R.id.tvdoors);
tv1.setText(Colour[position]);
tv2.setText(FuelType[position]);
tv3.setText(Manufacturer[position]);
tv4.setText(Model[position]);
tv5.setText(Reg[position]);
tv6.setText(EngineSize[position]);
tv7.setText(Doors[position]);
return (row);
}
****** ****编辑 好的家伙经过大量的测试和搞乱这是我在... 如果我从我的数据库参考结束
中删除行reg子项dbref = db.getReference().child(Cars).child(reg);
喜欢这个
dbref = db.getReference().child(Cars);
它使用我的“汽车”部分中的所有数据填充列表。我只是想要汽车我正在寻找。只是不明白为什么当我搜索孩子（reg）它返回空白
****另一个编辑***** 进一步tersting香港专业教育学院发现，如果添加汽车数据，如果添加额外的孩子为reg进入它工作。所以现在数据库看起来像这样
汽车----＆GT;
Kj65YHT（以制造注册为例） ---＆GT; Kj65YHT（这是额外的孩子，我不得不补充说这是错的吗？） ---＆GT;
制造商福特
模特嘉年华
门2
enginesize 1600
reg Kj65YHT