您的stackoverflow在这个错误中呆了半个星期，试图将我的图像从网格视图转到包含喜欢和评论列表的另一个片段，因此erorr始终指向此行204 ..做了一个日志，并成功获取了它所有数据，但无法正常工作
public class ProfileFragment extends Fragment {
private static final String TAG = "ProfileFragment";
public interface OnGridImageSelectedListener{
void onGridImageSelected(Photo photo);
}
OnGridImageSelectedListener mOnGridImageSelectedListener;
private CircleImageView mProfilePhoto;
private GridView gridView;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.profile_fargment, container, false);
mDisplayName = (TextView) view.findViewById(R.id.display_name);
mUsername = (TextView) view.findViewById(R.id.username);
mWebsite = (TextView) view.findViewById(R.id.website);
mDescription = (TextView) view.findViewById(R.id.description);
mProfilePhoto = (CircleImageView) view.findViewById(R.id.profile_photo);
mPosts = (TextView) view.findViewById(R.id.tvPosts);
mFriends = (TextView) view.findViewById(R.id.tvFollowing);
mProgressBar = (ProgressBar) view.findViewById(R.id.profileProgressBar);
gridView = (GridView) view.findViewById(R.id.gridView1);
toolbar = (Toolbar) view.findViewById(R.id.profileToolBar);
// profileMenu = (ImageView) view.findViewById(R.id.profileMenu);
bottomNavigationView = (BottomNavigationViewEx) view.findViewById(R.id.bottomNavViewBar);
mContext = getActivity();
mFirebaseMethods = new FirebaseMethods(getActivity());
Log.d(TAG, "onCreateView: stared.");
// setupBottomNavigationView();
// setupToolbar();
setupFirebaseAuth();
setupGridView();
@Override
public void onAttach(Context context) {
try{
mOnGridImageSelectedListener = (OnGridImageSelectedListener) getActivity();
}catch (ClassCastException e){
Log.e(TAG, "onAttach: ClassCastException: " + e.getMessage() );
}
super.onAttach(context);
}
private void setupGridView(){
Log.d(TAG, "setupGridView: Setting up image grid.");
final ArrayList<Photo> photos = new ArrayList<>();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference
.child(getString(R.string.dbname_user_photos))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot singleSnapshot : dataSnapshot.getChildren()) {
Photo photo = new Photo();
Map<String, Object> objectMap = (HashMap<String, Object>) singleSnapshot.getValue();
photo.setCaption(objectMap.get(getString(R.string.field_caption)).toString());
photo.setTags(objectMap.get(getString(R.string.field_tags)).toString());
photo.setPhoto_id(objectMap.get(getString(R.string.field_photo_id)).toString());
photo.setUser_id(objectMap.get(getString(R.string.field_user_id)).toString());
photo.setDate_created(objectMap.get(getString(R.string.field_date_created)).toString());
photo.setImage_path(objectMap.get(getString(R.string.field_image_path)).toString());
List<Like> likesList = new ArrayList<Like>();
for (DataSnapshot dSnapshot : singleSnapshot
.child(getString(R.string.field_likes)).getChildren()) {
Like like = new Like();
like.setUser_id(dSnapshot.getValue(Like.class).getUser_id());
likesList.add(like);
}
photo.setLikes(likesList);
photos.add(photo);
}
//setup our image grid
int gridWidth = getResources().getDisplayMetrics().widthPixels;
int imageWidth = gridWidth / NUM_GRID_COLUMNS;
gridView.setColumnWidth(imageWidth);
ArrayList<String> imgUrls = new ArrayList<>();
for (int i = 0; i < photos.size(); i++) {
imgUrls.add(photos.get(i).getImage_path());
}
final GridImageAdapter adapter = new GridImageAdapter(getActivity(), R.layout.layout_grid_imageview,
"", imgUrls);
gridView.setAdapter(adapter);
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(@Nullable AdapterView<?> parent, View view, int position, long id) {
//this works
Log.d(TAG, "onItemClick: position is at " + photos.get(position));
//this is line 204 that dont work
mOnGridImageSelectedListener.onGridImageSelected(photos.get(position));
}
});
}
@Override
public void onCancelled(DatabaseError databaseError) {
Log.d(TAG, "onCancelled: query cancelled.");
}
});
}
此视图的文章布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:id="@+id/relLayout1">
<de.hdodenhof.circleimageview.CircleImageView
android:layout_width="30dp"
android:layout_height="30dp"
android:id="@+id/profile_photo"
android:layout_marginTop="20dp"
app:civ_border_color="@color/black"
app:civ_border_width="0.5dp"
android:layout_marginLeft="25dp"
android:layout_centerVertical="true"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="mitch.tabian"
android:layout_toRightOf="@+id/profile_photo"
android:layout_marginLeft="10dp"
android:layout_centerVertical="true"
android:id="@+id/username"
android:textColor="@color/black"
/>
<ImageView
android:layout_width="30dp"
android:layout_height="30dp"
android:src="@drawable/ic_post_settings"
android:layout_centerVertical="true"
android:layout_alignParentRight="true"
android:layout_marginRight="20dp"
android:id="@+id/ivEllipses"/>
</RelativeLayout>
<com.nuc.zack.garmd.Utils.SqaureImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/post_image"
android:layout_below="@id/relLayout1"
android:scaleType="centerCrop"/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="50dp"
android:id="@+id/relLayout2"
android:layout_below="@+id/post_image"
android:background="@color/white">
<RelativeLayout
android:layout_width="60dp"
android:layout_height="match_parent"
android:id="@+id/heartLayout"
android:background="@color/white">
<ImageView
android:layout_width="35dp"
android:layout_height="35dp"
android:id="@+id/image_heart_red"
android:layout_centerInParent="true"
android:layout_marginLeft="20dp"
android:src="@drawable/ic_heart_red"
android:visibility="invisible"/>
<ImageView
android:layout_width="35dp"
android:layout_height="35dp"
android:id="@+id/image_heart"
android:layout_centerInParent="true"
android:layout_marginLeft="20dp"
android:src="@drawable/ic_heart_white"
android:visibility="visible"/>
</RelativeLayout>
<ImageView
android:layout_width="35dp"
android:layout_height="35dp"
android:id="@+id/speech_bubble"
android:layout_toRightOf="@+id/heartLayout"
android:layout_marginLeft="10dp"
android:src="@drawable/ic_speech_bubble"
android:visibility="visible"
android:layout_centerVertical="true"/>
<ImageView
android:layout_width="35dp"
android:layout_height="35dp"
android:id="@+id/imageShare"
android:layout_toRightOf="@+id/speech_bubble"
android:layout_marginLeft="10dp"
android:src="@drawable/ic_share_post"
android:visibility="visible"
android:layout_centerVertical="true"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/relLayout3"
android:layout_below="@+id/relLayout2"
android:padding="20dp"
android:layout_marginBottom="50dp"
android:background="@color/white">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Liked by Mitch, Tom, Mohammed and 30 others"
android:textColor="@color/black"
android:textSize="18sp"
android:id="@+id/likes"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="mitch.tabian moutains #earthporn #mountains"
android:textColor="@color/black"
android:textSize="18sp"
android:id="@+id/caption"
android:layout_below="@+id/likes"
android:layout_marginTop="15dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="View all 3 comments"
android:textColor="@color/grey"
android:textSize="18sp"
android:layout_below="@+id/caption"
android:id="@+id/comments"
android:layout_marginTop="15dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="3 DAYS AGO"
android:textColor="@color/grey"
android:textSize="18sp"
android:layout_below="@+id/comments"
android:id="@+id/image_time_posted"
android:layout_marginTop="15dp"/>
</RelativeLayout>
</RelativeLayout>
</ScrollView>
<include layout="@layout/layout_bottom_navigation_view"/>
</RelativeLayout>
viwepost片段
public class ViewPostFragment extends Fragment {
private static final String TAG = "ViewPostFragment";
public ViewPostFragment(){
super();
setArguments(new Bundle());
}
//widgets
private SqaureImageView mPostImage;
private BottomNavigationViewEx bottomNavigationView;
private TextView mBackLabel, mCaption, mUsername, mTimestamp, mLikes;
private ImageView mBackArrow, mEllipses, mHeartRed, mHeartWhite, mProfileImage;
//vars
private Photo mPhoto;
private int mActivityNumber = 0;
private String photoUsername = "";
private String profilePhotoUrl = "";
private UserAccount mUserAccountSettings;
private GestureDetector mGestureDetector;
private Heart mHeart;
private Boolean mLikedByCurrentUser;
private StringBuilder mUsers;
private String mLikesString = "";
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_view_post, container, false);
mPostImage = (SqaureImageView) view.findViewById(R.id.post_image);
bottomNavigationView = (BottomNavigationViewEx) view.findViewById(R.id.bottomNavViewBar);
mBackArrow = (ImageView) view.findViewById(R.id.backArrow);
mBackLabel = (TextView) view.findViewById(R.id.tvBackLabel);
mCaption = (TextView) view.findViewById(R.id.caption);
mUsername = (TextView) view.findViewById(R.id.username);
mTimestamp = (TextView) view.findViewById(R.id.image_time_posted);
mEllipses = (ImageView) view.findViewById(R.id.ivEllipses);
mHeartRed = (ImageView) view.findViewById(R.id.image_heart_red);
mHeartWhite = (ImageView) view.findViewById(R.id.image_heart);
mProfileImage = (ImageView) view.findViewById(R.id.profile_photo);
mLikes = (TextView) view.findViewById(R.id.likes);
mHeart = new Heart(mHeartWhite, mHeartRed);
mGestureDetector = new GestureDetector(getActivity(), new GestureListener());
try{
mPhoto = getPhotoFromBundle();
UniversalImageLoader.setImage(mPhoto.getImage_path(), mPostImage, null, "");
mActivityNumber = getActivityNumFromBundle();
getPhotoDetails();
getLikesString();
}catch (NullPointerException e){
Log.e(TAG, "onCreateView: NullPointerException: " + e.getMessage() );
}
setupFirebaseAuth();
setupBottomNavigationView();
return view;
}
private void getLikesString(){
Log.d(TAG, "getLikesString: getting likes string");
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference
.child(getString(R.string.dbname_photos))
.child(mPhoto.getPhoto_id())
.child(getString(R.string.field_likes));
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
mUsers = new StringBuilder();
for(DataSnapshot singleSnapshot : dataSnapshot.getChildren()){
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference
.child(getString(R.string.dbname_user))
.orderByChild(getString(R.string.field_user_id))
.equalTo(singleSnapshot.getValue(Like.class).getUser_id());
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot singleSnapshot : dataSnapshot.getChildren()){
Log.d(TAG, "onDataChange: found like: " +
singleSnapshot.getValue(User.class).getUser_name());
mUsers.append(singleSnapshot.getValue(User.class).getUser_name());
mUsers.append(",");
}
String[] splitUsers = mUsers.toString().split(",");
if(mUsers.toString().contains(mUserAccountSettings.getUser_name())){
mLikedByCurrentUser = true;
}else{
mLikedByCurrentUser = false;
}
int length = splitUsers.length;
if(length == 1){
mLikesString = "Liked by " + splitUsers[0];
}
else if(length == 2){
mLikesString = "Liked by " + splitUsers[0]
+ " and " + splitUsers[1];
}
else if(length == 3){
mLikesString = "Liked by " + splitUsers[0]
+ ", " + splitUsers[1]
+ " and " + splitUsers[2];
}
else if(length == 4){
mLikesString = "Liked by " + splitUsers[0]
+ ", " + splitUsers[1]
+ ", " + splitUsers[2]
+ " and " + splitUsers[3];
}
else if(length > 4){
mLikesString = "Liked by " + splitUsers[0]
+ ", " + splitUsers[1]
+ ", " + splitUsers[2]
+ " and " + (splitUsers.length - 3) + " others";
}
Log.d(TAG, "onDataChange: likes string: " + mLikesString);
setupWidgets();
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
if(!dataSnapshot.exists()){
mLikesString = "";
mLikedByCurrentUser = false;
setupWidgets();
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
public class GestureListener extends GestureDetector.SimpleOnGestureListener{
@Override
public boolean onDown(MotionEvent e) {
return true;
}
@Override
public boolean onDoubleTap(MotionEvent e) {
Log.d(TAG, "onDoubleTap: double tap detected.");
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference
.child(getString(R.string.dbname_photos))
.child(mPhoto.getPhoto_id())
.child(getString(R.string.field_likes));
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot singleSnapshot : dataSnapshot.getChildren()){
String keyID = singleSnapshot.getKey();
//case1: Then user already liked the photo
if(mLikedByCurrentUser &&
singleSnapshot.getValue(Like.class).getUser_id()
.equals(FirebaseAuth.getInstance().getCurrentUser().getUid())){
myRef.child(getString(R.string.dbname_photos))
.child(mPhoto.getPhoto_id())
.child(getString(R.string.field_likes))
.child(keyID)
.removeValue();
///
myRef.child(getString(R.string.dbname_user_photos))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(mPhoto.getPhoto_id())
.child(getString(R.string.field_likes))
.child(keyID)
.removeValue();
mHeart.toggleLike();
getLikesString();
}
//case2: The user has not liked the photo
else if(!mLikedByCurrentUser){
//add new like
addNewLike();
break;
}
}
if(!dataSnapshot.exists()){
//add new like
addNewLike();
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
return true;
}
}
private void addNewLike(){
Log.d(TAG, "addNewLike: adding new like");
String newLikeID = myRef.push().getKey();
Like like = new Like();
like.setUser_id(FirebaseAuth.getInstance().getCurrentUser().getUid());
myRef.child(getString(R.string.dbname_photos))
.child(mPhoto.getPhoto_id())
.child(getString(R.string.field_likes))
.child(newLikeID)
.setValue(like);
myRef.child(getString(R.string.dbname_user_photos))
.child(FirebaseAuth.getInstance().getCurrentUser().getUid())
.child(mPhoto.getPhoto_id())
.child(getString(R.string.field_likes))
.child(newLikeID)
.setValue(like);
mHeart.toggleLike();
getLikesString();
}
private void getPhotoDetails(){
Log.d(TAG, "getPhotoDetails: retrieving photo details.");
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference
.child(getString(R.string.dbname_user_account))
.orderByChild(getString(R.string.field_user_id))
.equalTo(mPhoto.getUser_id());
query.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for ( DataSnapshot singleSnapshot : dataSnapshot.getChildren()){
mUserAccountSettings = singleSnapshot.getValue(UserAccount.class);
}
//setupWidgets();
}
@Override
public void onCancelled(DatabaseError databaseError) {
Log.d(TAG, "onCancelled: query cancelled.");
}
});
}
private void setupWidgets(){
String timestampDiff = getTimestampDifference();
if(!timestampDiff.equals("0")){
mTimestamp.setText(timestampDiff + " DAYS AGO");
}else{
mTimestamp.setText("TODAY");
}
UniversalImageLoader.setImage(mUserAccountSettings.getProfile_photo(), mProfileImage, null, "");
mUsername.setText(mUserAccountSettings.getProfile_photo());
mLikes.setText(mLikesString);
if(mLikedByCurrentUser){
mHeartWhite.setVisibility(View.GONE);
mHeartRed.setVisibility(View.VISIBLE);
mHeartRed.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
Log.d(TAG, "onTouch: red heart touch detected.");
return mGestureDetector.onTouchEvent(event);
}
});
}
else{
mHeartWhite.setVisibility(View.VISIBLE);
mHeartRed.setVisibility(View.GONE);
mHeartWhite.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
Log.d(TAG, "onTouch: white heart touch detected.");
return mGestureDetector.onTouchEvent(event);
}
});
}
}
/**
* Returns a string representing the number of days ago the post was made
* @return
*/
private String getTimestampDifference(){
Log.d(TAG, "getTimestampDifference: getting timestamp difference.");
String difference = "";
Calendar c = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.CANADA);
sdf.setTimeZone(TimeZone.getTimeZone("Canada/Pacific"));//google 'android list of timezones'
Date today = c.getTime();
sdf.format(today);
Date timestamp;
final String photoTimestamp = mPhoto.getDate_created();
try{
timestamp = sdf.parse(photoTimestamp);
difference = String.valueOf(Math.round(((today.getTime() - timestamp.getTime()) / 1000 / 60 / 60 / 24 )));
}catch (ParseException e){
Log.e(TAG, "getTimestampDifference: ParseException: " + e.getMessage() );
difference = "0";
}
return difference;
}
/**
* retrieve the activity number from the incoming bundle from profileActivity interface
* @return
*/
private int getActivityNumFromBundle(){
Log.d(TAG, "getActivityNumFromBundle: arguments: " + getArguments());
Bundle bundle = this.getArguments();
if(bundle != null) {
return bundle.getInt(getString(R.string.activity_number));
}else{
return 0;
}
}
/**
* retrieve the photo from the incoming bundle from profileActivity interface
* @return
*/
private Photo getPhotoFromBundle(){
Log.d(TAG, "getPhotoFromBundle: arguments: " + getArguments());
Bundle bundle = this.getArguments();
if(bundle != null) {
return bundle.getParcelable(getString(R.string.photo));
}else{
return null;
}
}
/**
* BottomNavigationView setup
*/
private void setupBottomNavigationView(){
Log.d(TAG, "setupBottomNavigationView: setting up BottomNavigationView");
BottomNavigationViewHelper.setupBottomNavigationView(bottomNavigationView);
BottomNavigationViewHelper.enableNavigation(getActivity(),getActivity() ,bottomNavigationView);
Menu menu = bottomNavigationView.getMenu();
MenuItem menuItem = menu.getItem(mActivityNumber);
menuItem.setChecked(true);
}
}
logcat
10-04 19:10:55.563 3171-3171/com.sdad.fd E/AndroidRuntime: FATAL EXCEPTION: main
java.lang.NullPointerException
at com.sdad.fd.Profile.ProfileFragment$2$1.onItemClick(ProfileFragment.java:207)
at android.widget.AdapterView.performItemClick(AdapterView.java:298)
at android.widget.AbsListView.performItemClick(AbsListView.java:1100)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:2788)
at android.widget.AbsListView$1.run(AbsListView.java:3463)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
预先感谢
ps在每个文档中寻找错误，并尝试切换到Intent并没有成功
将接口从片段类中取出到它自己的类中，在片段中实现它，在片段内部实现onGridImageSelected（），然后从onItemClick（）调用它。