Android 没有数据可从fire#u基地和那里检索';适配器有故障
E/RecyclerView:未连接适配器;跳过布局#1 这是我第一次构建应用程序时收到的消息,有什么帮助吗 公共类映像\u活动扩展了AppCompatActivity{Android 没有数据可从fire#u基地和那里检索';适配器有故障,android,firebase,firebase-realtime-database,android-recyclerview,Android,Firebase,Firebase Realtime Database,Android Recyclerview,E/RecyclerView:未连接适配器;跳过布局#1 这是我第一次构建应用程序时收到的消息,有什么帮助吗 公共类映像\u活动扩展了AppCompatActivity{ private RecyclerView mRecyclerView; private ImageAdapter mAdapter; private ProgressBar mProgressCircle; private DatabaseReference mDatabaseRef; private List<Up
private RecyclerView mRecyclerView;
private ImageAdapter mAdapter;
private ProgressBar mProgressCircle;
private DatabaseReference mDatabaseRef;
private List<Upload> mUploads;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_images_);
mRecyclerView = findViewById(R.id.recycler_view);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mProgressCircle = findViewById(R.id.progress_circle);
mUploads = new ArrayList<>();
mDatabaseRef = FirebaseDatabase.getInstance().getReference("uploads");
mDatabaseRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
Upload upload = postSnapshot.getValue(Upload.class);
mUploads.add(upload);
}
mAdapter = new ImageAdapter(Images_Activity.this, mUploads);
mRecyclerView.setAdapter(mAdapter);
mProgressCircle.setVisibility(View.INVISIBLE);
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
mProgressCircle.setVisibility(View.INVISIBLE);
}
});
}
private RecyclerView mRecyclerView;
专用图像适配器mAdapter;
私人ProgressBar mProgressCircle;
私有数据库引用mDatabaseRef;
私人列表多路复用器;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u图像);
mRecyclerView=findviewbyd(R.id.recycler\u视图);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(新的LinearLayoutManager(this));
mProgressCircle=findviewbyd(R.id.progress\u circle);
mUploads=newarraylist();
mDatabaseRef=FirebaseDatabase.getInstance().getReference(“上载”);
mDatabaseRef.addValueEventListener(新的ValueEventListener(){
@凌驾
公共void onDataChange(DataSnapshot DataSnapshot){
对于(DataSnapshot postSnapshot:DataSnapshot.getChildren()){
Upload Upload=postSnapshot.getValue(Upload.class);
添加(上传);
}
mAdapter=新的ImageAdapter(Images\u Activity.this,mUploads);
mRecyclerView.setAdapter(mAdapter);
mProgressCircle.setVisibility(视图.不可见);
}
@凌驾
已取消的公共void(@NonNull DatabaseError DatabaseError){
mProgressCircle.setVisibility(视图.不可见);
}
});
}
}您不需要执行
mRecyclerView.setAdapter(mAdapter)代码>在事件侦听器中
在监听器外部或甚至在valueEventListener可以工作之前将其置于监听器外部后仍然存在相同的问题:/查看databaseError给出的消息您是否尝试使用而不是Images\u活动。此
调用getApplicationContext()
方法?