MainActivity
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
public static final String ANONYMOUS = "anonymous";
public static final int RC_SIGN_IN = 1;
private static final int RC_PHOTO_PICKER = 2;
private String mUsername;
// Firebase instance variables
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mMessagesDatabaseReference;
private ChildEventListener mChildEventListener;
private FirebaseAuth mFirebaseAuth;
private FirebaseAuth.AuthStateListener mAuthStateListener;
private FirebaseStorage mFirebaseStorage;
private StorageReference mChatPhotosStorageReference;
private FirebaseRemoteConfig mFirebaseRemoteConfig;
private RecyclerView recyclerView;
private FloatingActionButton floatingActionButton;
PhotosAdapter contactsAdapter;
List<Photos> contactList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mUsername = ANONYMOUS;
recyclerView=(RecyclerView)findViewById(R.id.recyclerview);
floatingActionButton=(FloatingActionButton)findViewById(R.id.floatingactionbutton);
contactList = new ArrayList();
contactsAdapter=new PhotosAdapter(contactList,getApplicationContext());
// Initialize Firebase components
mFirebaseDatabase = FirebaseDatabase.getInstance();
mFirebaseAuth = FirebaseAuth.getInstance();
mFirebaseStorage = FirebaseStorage.getInstance();
mFirebaseRemoteConfig = FirebaseRemoteConfig.getInstance();
mMessagesDatabaseReference = mFirebaseDatabase.getReference().child("messages");
mChatPhotosStorageReference = mFirebaseStorage.getReference().child("chat_photos");
mAuthStateListener = new FirebaseAuth.AuthStateListener() {
@Override
public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
FirebaseUser user = firebaseAuth.getCurrentUser();
if (user != null) {
// User is signed in
onSignedInInitialize(user.getDisplayName());
} else {
// User is signed out
onSignedOutCleanup();
startActivityForResult(
AuthUI.getInstance()
.createSignInIntentBuilder()
.setIsSmartLockEnabled(false)
.setProviders(
AuthUI.EMAIL_PROVIDER,
AuthUI.GOOGLE_PROVIDER)
.build(),
RC_SIGN_IN);
}
}
};
recyclerView.setAdapter(contactsAdapter);
recyclerView.setLayoutManager(new GridLayoutManager(getApplicationContext(),5));
floatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/jpeg");
intent.putExtra(Intent.EXTRA_LOCAL_ONLY, true);
startActivityForResult(Intent.createChooser(intent, "Complete action using"), RC_PHOTO_PICKER);
}
});
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == RC_SIGN_IN) {
if (resultCode == RESULT_OK) {
// Sign-in succeeded, set up the UI
Toast.makeText(this, "Signed in!", Toast.LENGTH_SHORT).show();
} else if (resultCode == RESULT_CANCELED) {
// Sign in was canceled by the user, finish the activity
Toast.makeText(this, "Sign in canceled", Toast.LENGTH_SHORT).show();
finish();
}
}else if (requestCode == RC_PHOTO_PICKER && resultCode == RESULT_OK) {
Uri selectedImageUri = data.getData();
// Get a reference to store file at chat_photos/<FILENAME>
StorageReference photoRef = mChatPhotosStorageReference.child(selectedImageUri.getLastPathSegment());
// Upload file to Firebase Storage
photoRef.putFile(selectedImageUri)
.addOnSuccessListener(this, new OnSuccessListener<UploadTask.TaskSnapshot>() {
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
// When the image has successfully uploaded, we get its download URL
Uri downloadUrl = taskSnapshot.getDownloadUrl();
// Set the download URL to the message box, so that the user can send it to the database
Photos friendlyMessage = new Photos(downloadUrl.toString());
mMessagesDatabaseReference.push().setValue(friendlyMessage);
}
});
}
}
@Override
protected void onResume() {
super.onResume();
mFirebaseAuth.addAuthStateListener(mAuthStateListener);
}
@Override
protected void onPause() {
super.onPause();
if (mAuthStateListener != null) {
mFirebaseAuth.removeAuthStateListener(mAuthStateListener);
}
}
private void onSignedInInitialize(String username) {
mUsername = username;
attachDatabaseReadListener();
}
private void onSignedOutCleanup() {
mUsername = ANONYMOUS;
}
private void attachDatabaseReadListener() {
if (mChildEventListener == null) {
mChildEventListener = new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Photos friendlyMessage = dataSnapshot.getValue(Photos.class);
contactsAdapter.add(friendlyMessage);
}
public void onChildChanged(DataSnapshot dataSnapshot, String s) {}
public void onChildRemoved(DataSnapshot dataSnapshot) {}
public void onChildMoved(DataSnapshot dataSnapshot, String s) {}
public void onCancelled(DatabaseError databaseError) {}
};
mMessagesDatabaseReference.addChildEventListener(mChildEventListener);
}
}
}
PhotosAdapter
public class PhotosAdapter extends RecyclerView.Adapter<PhotosAdapter.MyViewHolder> {
private List<Photos> photosList;
private Context context;
public static final String Position="AdapterPosition";
public PhotosAdapter(List<Photos> contactsList, Context context) {
this.photosList = contactsList;
this.context = context;
}
@Override
public PhotosAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.list_item, null);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(PhotosAdapter.MyViewHolder holder, int position) {
Photos contacts = photosList.get(position);
Glide.with(context).load(contacts.getPhotoUrl()).into(holder.contactimageView);
}
@Override
public int getItemCount() {
return photosList.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
public ImageView contactimageView;
private final Context context;
public MyViewHolder(View itemView) {
super(itemView);
context = itemView.getContext();
contactimageView = (ImageView) itemView.findViewById(R.id.imageview);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View v) {
/* Intent intent = new Intent(context, ChatActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra(Position,getAdapterPosition());
context.startActivity(intent);*/
}
public void add(Photos photos){
photosList.add(photos);
}
}
照片
public class Photos {
private String photoUrl;
public Photos() {
}
public Photos(String photoUrl) {
this.photoUrl = photoUrl;
}
public String getPhotoUrl() {
return photoUrl;
}
public void setPhotoUrl(String photoUrl) {
this.photoUrl = photoUrl;
}
}
这是我的代码。我正在点击FloatingAction按钮上传图片到Firebase存储。图片上传成功，但我无法将图片检索到我的ImageView RecyclerView }。我究竟做错了什么？我还能够在Storage.Still中看到图像的URL，无法在recyclerview的imageview中检索消息。请帮助.......
答案 0 :(得分：0)
你也可以试试这个： -
yourFragment.isResumed()