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Ich benutze Firebase für meine Android-App. Ich habe einige Bilder im Speicherbereich der Firebase hochgeladen und in der Listenansicht angezeigt. Wenn ich nun auf ein bestimmtes Bild der Recycleransicht klicke, möchte ich zur nächsten Aktivität gehen und das Bild anzeigen, auf das ich in der Bildansicht der nächsten Aktivität geklickt habe. Wie kann ich dieses bestimmte Bild abrufen? Bitte helfen Sie.Wie man Bild von Firebase basierend auf Klick zurückholen
Ich habe einen Fotoordner im Speicher meiner Firebase erstellt und alle Bilder werden in diesem Ordner gespeichert.
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
public static final String ANONYMOUS = "anonymous";
public static final int DEFAULT_MSG_LENGTH_LIMIT = 1000;
public static final String FRIENDLY_MSG_LENGTH_KEY = "friendly_msg_length";
public static final int RC_SIGN_IN = 1;
private static final int RC_PHOTO_PICKER = 2;
private ListView mMessageListView;
private MessageAdapter mMessageAdapter;
private ProgressBar mProgressBar;
private ImageButton mPhotoPickerButton;
private EditText mMessageEditText;
private Button mSendButton;
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;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mUsername = ANONYMOUS;
// Initialize Firebase components
mFirebaseDatabase = FirebaseDatabase.getInstance();
mFirebaseAuth = FirebaseAuth.getInstance();
mFirebaseStorage = FirebaseStorage.getInstance();
mFirebaseRemoteConfig = FirebaseRemoteConfig.getInstance();
mMessagesDatabaseReference = mFirebaseDatabase.getReference().child("messages");
mChatPhotosStorageReference = mFirebaseStorage.getReference().child("photos");
// Initialize references to views
mProgressBar = (ProgressBar) findViewById(R.id.progressBar);
mMessageListView = (ListView) findViewById(R.id.messageListView);
mPhotoPickerButton = (ImageButton) findViewById(R.id.photoPickerButton);
mMessageEditText = (EditText) findViewById(R.id.messageEditText);
mSendButton = (Button) findViewById(R.id.sendButton);
// Initialize message ListView and its adapter
List<FriendlyMessage> friendlyMessages = new ArrayList<>();
mMessageAdapter = new MessageAdapter(this, R.layout.item_message, friendlyMessages);
mMessageListView.setAdapter(mMessageAdapter);
// Initialize progress bar
mProgressBar.setVisibility(ProgressBar.INVISIBLE);
// ImagePickerButton shows an image picker to upload a image for a message
mPhotoPickerButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
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);
}
});
// Enable Send button when there's text to send
mMessageEditText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
if (charSequence.toString().trim().length() > 0) {
mSendButton.setEnabled(true);
} else {
mSendButton.setEnabled(false);
}
}
@Override
public void afterTextChanged(Editable editable) {
}
});
mMessageEditText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(DEFAULT_MSG_LENGTH_LIMIT)});
// Send button sends a message and clears the EditText
mSendButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
FriendlyMessage friendlyMessage = new FriendlyMessage(mMessageEditText.getText().toString(), mUsername, null);
mMessagesDatabaseReference.push().setValue(friendlyMessage);
// Clear input box
mMessageEditText.setText("");
}
});
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);
}
}
};
// Create Remote Config Setting to enable developer mode.
// Fetching configs from the server is normally limited to 5 requests per hour.
// Enabling developer mode allows many more requests to be made per hour, so developers
// can test different config values during development.
FirebaseRemoteConfigSettings configSettings = new FirebaseRemoteConfigSettings.Builder()
.setDeveloperModeEnabled(BuildConfig.DEBUG)
.build();
mFirebaseRemoteConfig.setConfigSettings(configSettings);
// Define default config values. Defaults are used when fetched config values are not
// available. Eg: if an error occurred fetching values from the server.
Map<String, Object> defaultConfigMap = new HashMap<>();
defaultConfigMap.put(FRIENDLY_MSG_LENGTH_KEY, DEFAULT_MSG_LENGTH_LIMIT);
mFirebaseRemoteConfig.setDefaults(defaultConfigMap);
fetchConfig();
}
@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
FriendlyMessage friendlyMessage = new FriendlyMessage(null, mUsername, 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);
}
mMessageAdapter.clear();
detachDatabaseReadListener();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main_menu, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.sign_out_menu:
AuthUI.getInstance().signOut(this);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void onSignedInInitialize(String username) {
mUsername = username;
attachDatabaseReadListener();
}
private void onSignedOutCleanup() {
mUsername = ANONYMOUS;
mMessageAdapter.clear();
detachDatabaseReadListener();
}
private void attachDatabaseReadListener() {
if (mChildEventListener == null) {
mChildEventListener = new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
FriendlyMessage friendlyMessage = dataSnapshot.getValue(FriendlyMessage.class);
mMessageAdapter.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);
}
}
private void detachDatabaseReadListener() {
if (mChildEventListener != null) {
mMessagesDatabaseReference.removeEventListener(mChildEventListener);
mChildEventListener = null;
}
}
// Fetch the config to determine the allowed length of messages.
public void fetchConfig() {
long cacheExpiration = 3600; // 1 hour in seconds
// If developer mode is enabled reduce cacheExpiration to 0 so that each fetch goes to the
// server. This should not be used in release builds.
if (mFirebaseRemoteConfig.getInfo().getConfigSettings().isDeveloperModeEnabled()) {
cacheExpiration = 0;
}
mFirebaseRemoteConfig.fetch(cacheExpiration)
.addOnSuccessListener(new OnSuccessListener<Void>() {
@Override
public void onSuccess(Void aVoid) {
// Make the fetched config available
// via FirebaseRemoteConfig get<type> calls, e.g., getLong, getString.
mFirebaseRemoteConfig.activateFetched();
// Update the EditText length limit with
// the newly retrieved values from Remote Config.
applyRetrievedLengthLimit();
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
// An error occurred when fetching the config.
Log.w(TAG, "Error fetching config", e);
// Update the EditText length limit with
// the newly retrieved values from Remote Config.
applyRetrievedLengthLimit();
}
});
}
/**
* Apply retrieved length limit to edit text field. This result may be fresh from the server or it may be from
* cached values.
*/
private void applyRetrievedLengthLimit() {
Long friendly_msg_length = mFirebaseRemoteConfig.getLong(FRIENDLY_MSG_LENGTH_KEY);
mMessageEditText.setFilters(new InputFilter[]{new InputFilter.LengthFilter(friendly_msg_length.intValue())});
Log.d(TAG, FRIENDLY_MSG_LENGTH_KEY + " = " + friendly_msg_length);
}
}
Bitte senden Sie Ihren vollständigen Code für die beste Verständnis. Vielen Dank! – user7439667
Bitte haben Sie einen Blick. Ich habe den Code –