我有同一应用程序的两个版本，一个管理员版本和一个客户端版本。
客户端版本可以报告以下紧急类型：
医疗援助、警察援助和消防援助
虽然管理版本的凭据上有部门：
警察、医院、消防局
我希望我的管理版本上的列表视图仅显示以下内容：
为管理员用户提供警察援助，为管理员用户提供医院医疗援助，等等...
这是我的数据库布局（我选择“警察”作为测试部门）：
{
"Admin Users": {
"vnpLogkr7pYndxx40XJB5PVulea2": {
"Department": {
"Fire Dept": 0,
"Hospital": 0,
"Police": 1
},
"Name": "Rafael Aurelius"
}
},
"Users": {
"W5RZg4leD0XR6ZWCNClr9Dt99XG3": {
"Scenario": "Scenario 2",
"emergencyType": "Police Assistance",
"userTimestamp": 1712208811229
}
}
我已经为每个部门设置了值，如果选择则为 1，如果未选择则为 0，因为我计划将过滤基于我之前实现的用户访问阻止系统，但到目前为止我还没有成功进行过滤.
这是没有过滤的列表视图：
package com.example.rescuealertadmin;
import static android.content.ContentValues.TAG;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import com.firebase.ui.database.FirebaseListAdapter;
import com.firebase.ui.database.FirebaseListOptions;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;
public class LocationLog extends AppCompatActivity {
FirebaseListAdapter<MainData> locationAdapter;
ListView locationList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_locationlog);
this.locationList = findViewById(R.id.locationView);
Query filteredQuery = FirebaseDatabase.getInstance().getReference().child("Users");
FirebaseListOptions<MainData> options = new FirebaseListOptions.Builder<MainData>()
.setLayout(R.layout.location_item)
.setQuery(filteredQuery, MainData.class)
.build();
locationList.setAdapter(locationAdapter);
locationAdapter = new FirebaseListAdapter<MainData>(options) {
@Override
protected void populateView(@NonNull View v, @NonNull MainData model, int position) {
TextView emergencyTypeView = v.findViewById(R.id.emergencyText);
TextView scenarioView = v.findViewById(R.id.ScenarioText);
Button emergencyButton = v.findViewById(R.id.itemButton);
emergencyTypeView.setText(model.getEmergencyType());
scenarioView.setText(model.getScenario());
String selectedUid = locationAdapter.getRef(position).getKey();
emergencyButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Get the location data of the selected user
assert selectedUid != null;
DatabaseReference selectedUserLocationRef = FirebaseDatabase.getInstance()
.getReference().child("User Location").child(selectedUid);
selectedUserLocationRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot locationSnapshot) {
if (locationSnapshot.exists()) {
Double latitude = locationSnapshot.child("latitude").getValue(Double.class);
Double longitude = locationSnapshot.child("longitude").getValue(Double.class);
if (latitude != null && longitude != null) {
// Data retrieved successfully, now start the new activity
Intent intent = new Intent(LocationLog.this, EmergencyDetails.class);
intent.putExtra("Emergency Type", model.getEmergencyType());
intent.putExtra("Scenario", model.getScenario());
intent.putExtra("Latitude", latitude);
intent.putExtra("Longitude", longitude);
startActivity(intent);
} else {
// Handle missing location data
Log.e(TAG, "Latitude or Longitude is null");
}
} else {
// Handle if the location data for the selected user doesn't exist
Log.e(TAG, "Location data does not exist for UID: " + selectedUid);
}
}
@Override
public void onCancelled(@NonNull DatabaseError locationError) {
// Handle location data retrieval error
Log.e(TAG, "Location data retrieval error: " + locationError.getMessage());
}
});
}
});
Log.d(TAG, "Emergency Type: " + model.getEmergencyType());
}
};
}
@Override
protected void onStart() {
super.onStart();
if (locationAdapter != null) {
locationAdapter.startListening();
}
}
@Override
protected void onStop() {
super.onStop();
if (locationAdapter != null) {
locationAdapter.stopListening();
}
}
}
在列表视图上成功过滤这些数据的方法有哪些？
根据评论中的答案，请使用以下代码行：
DatabaseReference db = FirebaseDatabase.getInstance().getReference();
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference uidRef = db.child("Admin Users").child(uid);
uidRef.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
@Override
public void onComplete(@NonNull Task<DataSnapshot> task) {
if (task.isSuccessful()) {
DataSnapshot snapshot = task.getResult();
DataSnapshot policeSnapshot = snapshot.child("Department").child("Police");
if (policeSnapshot.exists()) {
DatabaseReference usersRef = db.child("Users");
Query queryByDepartment = usersRef.orderByChild("emergencyType").equalTo("Police" + " Assistance");
queryByDepartment.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
@Override
public void onComplete(@NonNull Task<DataSnapshot> task) {
if (task.isSuccessful()) {
DataSnapshot usersSnapshot = task.getResult();
for (DataSnapshot userSnapshot : usersSnapshot.getChildren()) {
String scenario = userSnapshot.child("Scenario").getValue(String.class);
Log.d("TAG", scenario);
}
} else {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
}
});
}
} else {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
}
});
此代码读取经过身份验证的管理员的节点，然后检查
PoliceusersemergencyTypeScenarioScenario 2