感谢您的阅读。我正在开发MyAccountActivity，用户可以更改自己的个人资料图片。我在这里做的是当在onActivityResult（）方法中完成裁剪图像时，程序将更改当前用户的图像值。当图像值改变时，onCreate（）方法中的addValueEventListener将再次出现以读取该值并将该图像URL或字符串存储到Picasso中，就像我在addValueEventListener中一样。但是，应用程序只是在裁剪后自动签出。
通过打印出mImageUrl，我注意到当我成功裁剪图像时，它改变了值，但是一秒后它又回到了上一张图片，然后它将我退出。
任何人都可以帮助我吗？谢谢。
MyProfileActivity.java
public class MyProfileActivity extends AppCompatActivity
{
/*UI*/
private Toolbar mMyProfileToolbar;
private TextView mAge;
private TextView mGender;
private TextView mReligion;
private TextView mSports;
private TextView mState;
private TextView mTimeRegistered;
private TextView mDisplayName;
private CircleImageView mProfileImage;
/*Firebase*/
private DatabaseReference mDatabaseUser;
private FirebaseUser mUser;
private StorageReference mStorage;
private DatabaseReference mDatabasePost;
private StorageReference filepath;
private DatabaseReference user_db;
/*Other*/
private String age;
private String gender;
private String religion;
private String sports;
private String state;
private String timeRegistered;
private String displayName;
private Uri mImageUri = null;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my_profile);
/*UI*/
mMyProfileToolbar = (Toolbar)findViewById(R.id.activity_my_profile_toolbar);
mProfileImage = (CircleImageView)findViewById(R.id.activity_my_profile_profile_image);
mDisplayName = (TextView)findViewById(R.id.activity_my_profile_display_name);
mAge = (TextView)findViewById(R.id.activity_my_profile_age);
mGender = (TextView)findViewById(R.id.activity_my_profile_gender);
mReligion = (TextView)findViewById(R.id.activity_my_profile_religion);
mSports = (TextView)findViewById(R.id.activity_my_profile_sports);
mState = (TextView)findViewById(R.id.activity_my_profile_state);
mTimeRegistered = (TextView)findViewById(R.id.activity_my_profile_time_registered);
/*Firebase*/
mDatabaseUser = FirebaseDatabase.getInstance().getReference().child("User");
mUser = FirebaseAuth.getInstance().getCurrentUser();
mStorage = FirebaseStorage.getInstance().getReference();
/*Function*/
setSupportActionBar(mMyProfileToolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setTitle(null);
mDatabaseUser.child(mUser.getUid()).addValueEventListener(new ValueEventListener()
{
@Override
public void onDataChange(DataSnapshot dataSnapshot)
{
System.out.println("TestUp------------------------------------at addValueEventListener");
displayName = dataSnapshot.child("displayName").getValue().toString();
age = dataSnapshot.child("age").getValue().toString();
gender = dataSnapshot.child("gender").getValue().toString();
religion = dataSnapshot.child("religion").getValue().toString();
sports = dataSnapshot.child("sports").getValue().toString();
state = dataSnapshot.child("state").getValue().toString();
timeRegistered = dataSnapshot.child("timeRegistered").getValue().toString();
mImageUri = Uri.parse(dataSnapshot.child("image").getValue().toString());
System.out.println("TestUp------------------------------------mImageUri: " + mImageUri);
Picasso.with(MyProfileActivity.this).load(mImageUri).into(mProfileImage);
mDisplayName.setText(displayName);
mAge.setText("Age: " + age);
mGender.setText("Gender: " + gender);
mReligion.setText("Religion: " + religion);
mSports.setText("Sports: " + sports);
mState.setText("State: " + state);
mTimeRegistered.setText("Time Registered: " + timeRegistered);
}
@Override
public void onCancelled(DatabaseError databaseError)
{
}
});
mProfileImage.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Intent i = new Intent(Intent.ACTION_GET_CONTENT);
i.setType("image/*");
startActivityForResult(i, 1);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == 1 && resultCode == RESULT_OK)
{
mImageUri = data.getData();
CropImage.activity(mImageUri)
.setGuidelines(CropImageView.Guidelines.OFF)
.setAspectRatio(1, 1)
.start(this);
}
if(requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE)
{
CropImage.ActivityResult result = CropImage.getActivityResult(data);
if(resultCode == RESULT_OK)
{
mImageUri = result.getUri();
DatabaseReference user_db = mDatabaseUser.child(mUser.getUid());
user_db.child("image").setValue(mImageUri.toString());
System.out.println("TestDown------------------------------------user_db: " + user_db);
System.out.println("TestDown------------------------------------mImageUri: " + mImageUri);
}
else if(resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE)
{
System.out.println("Test9------------------------------------");
Toast.makeText(MyProfileActivity.this, "ERROR", Toast.LENGTH_SHORT).show();
Exception error = result.getError();
System.out.println("Test10------------------------------------");
}
}
}
}
Firebase实时数据库规则
{
"rules": {
// User profiles are only readable/writable by the user who owns it
".read": true,
".write": true,
"users": {
"$UID": {
".read": "auth.uid == $UID",
".write": "auth.uid == $UID"
}
},
// Posts can be read by anyone but only written by logged-in users.
"posts": {
".read": true,
".write": "auth.uid != null",
"$POSTID": {
// UID must matched logged in user and is fixed once set
"uid": {
".validate": "(data.exists() && data.val() == newData.val()) || newData.val() == auth.uid"
},
// User can only update own stars
"stars": {
"$UID": {
".validate": "auth.uid == $UID"
}
}
}
},
// User posts can be read by anyone but only written by the user that owns it,
// and with a matching UID
"user-posts": {
".read": true,
"$UID": {
"$POSTID": {
".write": "auth.uid == $UID",
".validate": "data.exists() || newData.child('uid').val() == auth.uid"
}
}
},
// Comments can be read by anyone but only written by a logged in user
"post-comments": {
".read": true,
".write": "auth.uid != null",
"$POSTID": {
"$COMMENTID": {
// UID must matched logged in user and is fixed once set
"uid": {
".validate": "(data.exists() && data.val() == newData.val()) || newData.val() == auth.uid"
}
}
}
}
}
}
答案 0 :(得分：0)
您可以在这种情况下使用单值侦听器。在你再次打电话之前，它不会听。
ref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
// Logic for success...
}
@Override
public void onCancelled(DatabaseError databaseError) {
// Logic for failure...
}
});
一次读取数据： 在某些情况下，您可能希望调用一次回调然后立即删除，例如在初始化您不希望更改的UI元素时。您可以使用addListenerForSingleValueEvent（）方法来简化此方案：它会触发一次，然后不会再次触发。