我有两个相同的活动ChatListActivity和FriendsList Activity。
第一个可以正常且快速地运行，但是第二个有时是空白的或不显示个人资料图片（在毕加索的帮助下）。尽管可以从Firebase正确接收所有信息。我使用的模型是相同的，基本上Friends.class扩展了Buddies.class。
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
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.ServerValue;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
import java.util.HashMap;
import java.util.Map;
import butterknife.BindView;
import butterknife.ButterKnife;
import de.hdodenhof.circleimageview.CircleImageView;
public class ChatListActivity extends AppCompatActivity {
private RecyclerView recyclerView_buddies;
private FirebaseRecyclerAdapter<Buddies, BuddiesViewHolder> firebaseRecyclerAdapter;
private DatabaseReference UsersDatabaseReference;
private DatabaseReference userDatabaseReference;
private FirebaseUser firebaseUser;
private FirebaseAuth firebaseAuth;
private static final String TAG = "Chat List Act:";
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference messageDatabaseReference;
private DatabaseReference BuddiesDatabaseReference;
private String mUserid;
private String friend_id;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_chat_list);
recyclerView_buddies = (RecyclerView) findViewById(R.id.RecycleView_chat_list);
recyclerView_buddies.setHasFixedSize(true);
recyclerView_buddies.setLayoutManager(new LinearLayoutManager(this));
firebaseAuth = FirebaseAuth.getInstance();
firebaseUser = firebaseAuth.getCurrentUser();
mFirebaseDatabase = FirebaseDatabase.getInstance();
userDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users").child(firebaseUser.getUid());
messageDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Messages");
UsersDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
BuddiesDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Messages").child(firebaseUser.getUid());
// Presence System
DatabaseReference connectedRef = FirebaseDatabase.getInstance().getReference(".info/connected");
connectedRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
boolean connected = snapshot.getValue(Boolean.class);
if (connected) {
System.out.println("connected");
} else {
DatabaseReference userLastOnlineRef = FirebaseDatabase.getInstance().getReference().child("Users")
.child(firebaseUser.getUid()).child("online");
userLastOnlineRef.onDisconnect().setValue("false");
System.out.println("not connected");
}
}
@Override
public void onCancelled(DatabaseError error) {
System.err.println("Listener was cancelled");
}
});
if (firebaseUser == null) {
//User is not logged in
Log.w(TAG, "Error. No user is logged in.");
finish();
startActivity(new Intent(this, LoginActivity.class));
}else {
final Map<String,Object> time_status = new HashMap<>();
time_status.put("time", ServerValue.TIMESTAMP);
time_status.put("online", "true");
userDatabaseReference.updateChildren(time_status);
Log.w(TAG, "Online status & time updated. edw");
}
messageDatabaseReference.keepSynced(true);
UsersDatabaseReference.keepSynced(true);
userDatabaseReference.keepSynced(true);
}
@Override
protected void onStart() {
super.onStart();
firebaseUser = firebaseAuth.getCurrentUser();
if (firebaseUser == null) {
//User is not logged in
Log.w(TAG, "Error. No user is logged in.");
finish();
startActivity(new Intent(this, LoginActivity.class));
}
Query conversationQuery = messageDatabaseReference.child("string").orderByChild("time");
FirebaseRecyclerOptions<Buddies> response = new FirebaseRecyclerOptions.Builder<Buddies>()
.setQuery(UsersDatabaseReference, Buddies.class)
.build();
firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Buddies, BuddiesViewHolder>(response) {
@Override
public BuddiesViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// Create a new instance of the ViewHolder, in this case we are using a custom
// layout called R.layout.message for each item
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.buddies_layout, parent, false);
return new BuddiesViewHolder(view);
}
@Override
protected void onBindViewHolder(final BuddiesViewHolder buddiesViewHolder, final int position, Buddies buddies) {
// Bind the Chat object to the ChatHolder
// ...
buddiesViewHolder.textView_Fullname.setText(buddies.getFullname());
buddiesViewHolder.textView_status.setText(buddies.getStatus());
if (!buddies.getProfile_pic().isEmpty()) {
String path = null;
path = buddies.getProfile_pic().toString();
Log.d(TAG, "path: " + buddies.getProfile_pic().toString());
Picasso.with(getApplicationContext())
.load(path)
.placeholder(R.mipmap.user_avatar_round)
.into(buddiesViewHolder.circleImageView_profile_pic);
}
buddiesViewHolder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String userid = getRef(position).getKey();
Intent intent = new Intent(getApplicationContext(), MessageActivity.class);
intent.putExtra("userid", userid);
startActivity(intent);
}
});
}
};
firebaseRecyclerAdapter.notifyDataSetChanged();
recyclerView_buddies.setAdapter(firebaseRecyclerAdapter);
firebaseRecyclerAdapter.startListening();
}
@Override
protected void onStop() {
super.onStop();
final Map<String,Object> time_status = new HashMap<>();
time_status.put("time", ServerValue.TIMESTAMP);
userDatabaseReference.updateChildren(time_status);
Log.w(TAG, "Online status updated.");
}
@Override
protected void onResume(){
super.onResume();
final Map<String, Object> time_status = new HashMap<>();
time_status.put("time", ServerValue.TIMESTAMP);
time_status.put("online", "true");
userDatabaseReference.updateChildren(time_status);
Log.w(TAG, "Online status updated. anoi3e");
}
@Override
protected void onRestart() {
super.onRestart();
final Map<String, Object> time_status = new HashMap<>();
time_status.put("time", ServerValue.TIMESTAMP);
time_status.put("online", "true");
userDatabaseReference.updateChildren(time_status);
Log.w(TAG, "Online status updated.");
}
/*
In future maybe the following function will be in separate file.
*/
public static class BuddiesViewHolder extends RecyclerView.ViewHolder {
View mView;
@BindView(R.id.textViewFullName)
TextView textView_Fullname;
@BindView(R.id.buddy_profile_picture)
CircleImageView circleImageView_profile_pic;
@BindView(R.id.TextView_User_Desc)
TextView textView_status;
public BuddiesViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
}
FriendsListActivity
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
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.ServerValue;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
import java.util.HashMap;
import java.util.Map;
import butterknife.BindView;
import butterknife.ButterKnife;
import de.hdodenhof.circleimageview.CircleImageView;
public class FriendsListActivity extends AppCompatActivity {
private RecyclerView recyclerView_buddies;
private FirebaseRecyclerAdapter<Friends, FriendsViewHolder> firebaseRecyclerAdapter;
private DatabaseReference FriendsDatabaseReference;
private DatabaseReference userDatabaseReference;
private DatabaseReference usersDatabaseReference;
private DatabaseReference mUsersDatabase;
private FirebaseUser firebaseUser;
private FirebaseAuth firebaseAuth;
private static final String TAG ="Friends Act:";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_friends_list);
recyclerView_buddies = (RecyclerView) findViewById(R.id.RecycleView_friends_list);
recyclerView_buddies.setHasFixedSize(true);
recyclerView_buddies.setLayoutManager(new LinearLayoutManager(this));
firebaseAuth = FirebaseAuth.getInstance();
firebaseUser = firebaseAuth.getCurrentUser();
FriendsDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Friends");
mUsersDatabase = FirebaseDatabase.getInstance().getReference().child("Friends").child(firebaseUser.getUid());
usersDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
userDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users").child(firebaseUser.getUid());
userDatabaseReference.keepSynced(true);
usersDatabaseReference.keepSynced(true);
FriendsDatabaseReference.keepSynced(true);
mUsersDatabase.keepSynced(true);
}
@Override
protected void onStart(){
super.onStart();
firebaseUser = firebaseAuth.getCurrentUser();
if( firebaseUser == null){
//User is not logged in
Log.w(TAG, "Error. No user is logged in.");
finish();
startActivity(new Intent(this, LoginActivity.class));
}
else {
final Map<String,Object> time_status = new HashMap<>();
time_status.put("time", ServerValue.TIMESTAMP);
userDatabaseReference.updateChildren(time_status);
Log.w(TAG, "Online status updated.");
}
// Presence System
DatabaseReference connectedRef = FirebaseDatabase.getInstance().getReference(".info/connected");
connectedRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
boolean connected = snapshot.getValue(Boolean.class);
if (connected) {
System.out.println("connected");
} else {
DatabaseReference userLastOnlineRef = FirebaseDatabase.getInstance().getReference().child("Users")
.child(firebaseUser.getUid()).child("online");
userLastOnlineRef.onDisconnect().setValue("false");
System.out.println("not connected");
}
}
@Override
public void onCancelled(DatabaseError error) {
System.err.println("Listener was cancelled");
}
});
FirebaseRecyclerOptions<Friends> response = new FirebaseRecyclerOptions.Builder<Friends>()
.setQuery( mUsersDatabase , Friends.class)
.build();
firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<Friends, FriendsViewHolder>(response) {
@Override
public FriendsViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// Create a new instance of the ViewHolder, in this case we are using a custom
// layout called R.layout.message for each item
View view = LayoutInflater.from(getApplicationContext())
.inflate(R.layout.buddies_layout, parent, false);
return new FriendsViewHolder(view);
}
@Override
protected void onBindViewHolder(final FriendsViewHolder friendsViewHolder, final int position, final Friends friends) {
// Bind the Chat object to the ChatHolder
// ...
// Next feature display since when they are friends
//friendsViewHolder.setDate(friends.getDate());
final String list_user_id = getRef(position).getKey();
usersDatabaseReference.child(list_user_id).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.hasChild("online")) {
String userOnline = dataSnapshot.child("online").getValue().toString();
friendsViewHolder.setUserOnline(userOnline);
Log.d(TAG, "User availability status: " + dataSnapshot.child("online").getValue().toString());
}
if(dataSnapshot.hasChild("profile_pic")) {
final String path = dataSnapshot.child("profile_pic").getValue().toString();
Log.d(TAG, "path: " + path);
friendsViewHolder.setUserImage(path, getApplicationContext());
}
if(dataSnapshot.hasChild("fullname")) {
//friendsViewHolder.textView_Fullname.setText(dataSnapshot.child("fullname").getValue().toString());
Log.w(TAG, "Friends name: "+ dataSnapshot.child("fullname").getValue().toString());
friendsViewHolder.setName(dataSnapshot.child("fullname").getValue().toString());
}
if(dataSnapshot.hasChild("status")) {
//friendsViewHolder.textView_status.setText(dataSnapshot.child("status").getValue().toString());
Log.w(TAG, "Friends status desc: "+ dataSnapshot.child("status").getValue().toString());
friendsViewHolder.setStatus(dataSnapshot.child("status").getValue().toString());
}
friendsViewHolder.mView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(getApplicationContext(), ViewFriendActivity.class);
intent.putExtra("userid", list_user_id);
startActivity(intent);
}
});
friendsViewHolder.mView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
CharSequence options[] = new CharSequence[]{"Open Profile", "Send message"};
final AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext());
builder.setTitle("Select Options");
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
//Click Event for each item.
if(i == 0){
Intent profileIntent = new Intent(getApplicationContext(), ViewFriendActivity.class);
profileIntent.putExtra("user_id", list_user_id);
startActivity(profileIntent);
}
if(i == 1){
Intent chatIntent = new Intent(getApplicationContext(), MessageActivity.class);
chatIntent.putExtra("user_id", list_user_id);
startActivity(chatIntent);
}
}
});
//builder.show();
return false;
}
});
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
};
firebaseRecyclerAdapter.notifyDataSetChanged();
recyclerView_buddies.setAdapter(firebaseRecyclerAdapter);
firebaseRecyclerAdapter.startListening();
}
@Override
protected void onStop() {
super.onStop();
firebaseRecyclerAdapter.stopListening();
final Map<String,Object> time_status = new HashMap<>();
time_status.put("time", ServerValue.TIMESTAMP);
userDatabaseReference.updateChildren(time_status);
Log.w(TAG, "Activity Stopped. Online status updated.");
}
/*
In future maybe the following function will be in separate file.
*/
public static class BuddiesViewHolder extends RecyclerView.ViewHolder {
View mView;
@BindView(R.id.textViewFullName)
TextView textView_Fullname;
@BindView(R.id.buddy_profile_picture)
CircleImageView circleImageView_profile_pic;
@BindView(R.id.TextView_User_Desc)
TextView textView_status;
public BuddiesViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
public static class FriendsViewHolder extends RecyclerView.ViewHolder {
View mView;
public FriendsViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setDate(String date){
TextView userStatusView = (TextView) mView.findViewById(R.id.TextView_User_Desc);
userStatusView.setText(date);
}
public void setName(String name){
TextView userNameView = (TextView) mView.findViewById(R.id.textViewFullName);
userNameView.setText(name);
}
public void setStatus(String status){
TextView textView_status = (TextView) mView.findViewById(R.id.TextView_User_Desc);
textView_status.setText(status);
}
public void setUserImage(String thumb_image, Context ctx){
CircleImageView userImageView = (CircleImageView) mView.findViewById(R.id.buddy_profile_picture);
Picasso.with(ctx).load(thumb_image).placeholder(R.mipmap.user_avatar_round).into(userImageView);
}
public void setUserOnline(String online_status) {
ImageView userOnlineView = (ImageView) mView.findViewById(R.id.buddy_profile_picture);
if(online_status.equals("true")){
userOnlineView.setVisibility(View.VISIBLE);
} else {
userOnlineView.setVisibility(View.INVISIBLE);
}
}
}
}
活动xml布局（它们是相同的。它们仅包含RecyclerView。
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:context="com.forthnet.dalva.bestbud.FriendsListActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/RecycleView_friends_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical">
</android.support.v7.widget.RecyclerView>
</LinearLayout>
ChatListActivity xml布局：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.forthnet.dalva.bestbud.ChatListActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/RecycleView_chat_list"
android:layout_width="match_parent"
android:layout_height="match_parent"></android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
更新问题
我检查了每个参数，发现这行代码是
ChatListActivity xml上的错误：
android:layout_height="wrap_content"
所以，我将其设置为
match_parent，尽管我还没有解决加载每个人头像的问题
用户。
最佳答案
我检查了每个参数，发现这行代码是ChatListActivity xml上的错误：
android:layout_height="wrap_content"
因此，我将其设置为
match_parent，尽管我没有解决加载每个用户的个人资料图片的问题，但最终它不是黑色的。我也发现我没有写这行作为评论...
userOnlineView.setVisibility(View.INVISIBLE);
这就是为什么所有图像都不可见的原因！