我想知道有多少用户当前已连接并正在从SQL Server访问内容？在我的情况下，当前时间非常重要。我正在使用SQL Server中的package com.app.whatsupafrica;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
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.ValueEventListener;
import com.squareup.picasso.Picasso;
import de.hdodenhof.circleimageview.CircleImageView;
/**
* A simple {@link Fragment} subclass.
*/
public class ChatsFragment extends Fragment
{
private View PrivateChatsView;
private RecyclerView chatsList;
private DatabaseReference ChatsRef, UsersRef;
private FirebaseAuth mAuth;
private String currentUserID;
public ChatsFragment()
{
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
PrivateChatsView = inflater.inflate(R.layout.fragment_chats, container, false);
mAuth = FirebaseAuth.getInstance();
currentUserID = mAuth.getUid();
if (mAuth.getUid() == null)
{
SendUserToLoginActivity();
}
if (! mAuth.getUid().isEmpty())
{
ChatsRef = FirebaseDatabase.getInstance().getReference().child("Contacts").child(mAuth.getUid());
}
UsersRef = FirebaseDatabase.getInstance().getReference().child("Users");
chatsList = (RecyclerView) PrivateChatsView.findViewById(R.id.chats_list);
chatsList.setLayoutManager(new LinearLayoutManager(getContext()));
return PrivateChatsView;
}
@Override
public void onStart()
{
super.onStart();
FirebaseRecyclerOptions<Contacts> options =
new FirebaseRecyclerOptions.Builder<Contacts>()
.setQuery(ChatsRef, Contacts.class)
.build();
FirebaseRecyclerAdapter<Contacts, ChatsViewHolder> adapter =
new FirebaseRecyclerAdapter<Contacts, ChatsViewHolder>(options) {
@Override
protected void onBindViewHolder(@NonNull final ChatsViewHolder holder, int position, @NonNull Contacts model)
{
final String usersIDs = getRef(position).getKey();
final String[] retImage = {"default_image"};
UsersRef.child(usersIDs).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot)
{
if (dataSnapshot.exists())
{
if (dataSnapshot.hasChild("image"))
{
retImage[0] = dataSnapshot.child("image").getValue().toString();
Picasso.get().load(retImage[0]).into(holder.profileImage);
}
final String retName = dataSnapshot.child("name").getValue().toString();
final String retStatus = dataSnapshot.child("status").getValue().toString();
holder.userName.setText(retName);
// holder.userStatus.setText("Last Seen: " + "\n" + "Date " + " Time");
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
Intent chatIntent = new Intent(getContext(), ChatActivity.class);
chatIntent.putExtra("visit_user_id", usersIDs);
chatIntent.putExtra("visit_user_name", retName);
chatIntent.putExtra("visit_image", retImage[0]);
startActivity(chatIntent);
}
});
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
@NonNull
@Override
public ChatsViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i)
{
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.users_display_layout, viewGroup, false);
return new ChatsViewHolder(view);
}
};
chatsList.setAdapter(adapter);
adapter.startListening();
}
public static class ChatsViewHolder extends RecyclerView.ViewHolder
{
CircleImageView profileImage;
TextView userStatus, userName;
public ChatsViewHolder(@NonNull View itemView)
{
super(itemView);
profileImage = itemView.findViewById(R.id.users_profile_image);
userStatus = itemView.findViewById(R.id.user_status);
userName = itemView.findViewById(R.id.user_profile_name);
}
}
private void SendUserToLoginActivity()
{
Intent loginIntent = new Intent(getContext(), LoginActivity.class);
startActivity(loginIntent);
}
}
和sys.sysprocess表。