FirebaseRecyclerAdapter对我不起作用
我需要父键和它的子键来表示RecycerView中的纬度和经度列表。我想我需要对FirebaseRecyclerAdapter中的PopulateViewholder中的LatlngsModel项做一些事情，但是不管做什么，我都做不对。
我目前循环所有的父键和它的子键作为它的许多父键，并将它添加到列表中...
JSON结构：
{
"users" : {
"0057242b-81e2-4f97-bca7-b671212614ba" : {
"email" : "kalle@hotmail.se",
"waypoints" : {
"-KH9UAPH5NmLJExaUa5g" : {
"-KH9UAPH5NmLJExaS2s" : {
"latitude" : 111,
"longitude" : 111.1
}
},
"-KHB1VjqUdO90vxj9XCh" : {
"-KHB1VjqUdO90vxj9XCi" : {
"latitude" : 222.1,
"longitude" : 222.11
},
"-KHB1ZykbwgXM9sPNie9" : {
"latitude" : 222.2,
"longitude" : 222.22
}
}
}
},
@JsonIgnoreProperties(ignoreUnknown=true)
public class User{
@JsonProperty("email")
String email;
MyWaypoint waypoints;
public User(){}
public User(String email){
this.email = email;
}
public String getEmail(){return this.email; }
public void setEmail(String _email){this.email = _email;}
public MyWaypoint getWaypoints(){return waypoints;}
public void setWaypoints(MyWaypoint points){ this.waypoints = points;}
}
纬度和经度POJO。
@JsonIgnoreProperties(ignoreUnknown = true)
public class MyWaypoint {
private double latitude;
private double longitude;
public MyWaypoint() {
}
public MyWaypoint(double latitude, double longitude) {
this.latitude = latitude;
this.longitude = longitude;
}
public double getLatitude() {
return latitude;
}
public double getLongitude() {
return longitude;
}
}
我的活动
public class MapListActivityRealBack2 extends AppCompatActivity {
private String LOG_TAG = "LOG_TAG";
private Firebase mRef;
private Firebase userRef;
private String mUserId;
FirebaseRecyclerAdapter<User, LatLngViewHolderBack2> mAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mRef = new Firebase(Constants.FIREBASE_URL);
if (mRef.getAuth() == null) {
loadLoginView();
}
try {
mUserId = mRef.getAuth().getUid();
} catch (Exception e) {
loadLoginView();
}
final RecyclerView mRecyclerView = (RecyclerView) findViewById(R.id.card_recycler_view);
mRecyclerView.setHasFixedSize(false);
LinearLayoutManager manager = new LinearLayoutManager(this);
manager.setReverseLayout(false);
mRecyclerView.setLayoutManager(manager);
// https://todoapprj.firebaseio.com/users/1a96a633-7e67-41b8-9aa7-c70d4b7eb59c
final String userUrl = Constants.FIREBASE_URL + "/users/" + mUserId;
userRef = new Firebase(userUrl);
mAdapter = new FirebaseRecyclerAdapter<User, LatLngViewHolderBack2>(User.class, R.layout.list_item, LatLngViewHolderBack2.class, userRef) {
@Override
protected void populateViewHolder(final LatLngViewHolderBack2 latLngViewHolder, User item, final int i) {
userRef.addValueEventListener(new ValueEventListener() {
List<MyWaypoint> userWayPointsList = new ArrayList<MyWaypoint>();
@Override
public void onDataChange(DataSnapshot wayPointsDataSnapshot) {
if(wayPointsDataSnapshot.getChildrenCount() > 0){
for (DataSnapshot wayPointsSnapshotChild : wayPointsDataSnapshot.getChildren()){
Log.i("FireBaseTester", "For-Loop :: wayPointsSnapshotChild.getValue() : "+wayPointsSnapshotChild.getValue());
if(wayPointsSnapshotChild.getChildrenCount()>0){
for (DataSnapshot wayPointsChild : wayPointsSnapshotChild.getChildren()){
//this is where we get the Lat and Lon
double latitude = Double.parseDouble(wayPointsChild.child("latitude").getValue().toString());
double longitude = Double.parseDouble(wayPointsChild.child("longitude").getValue().toString());
userWayPointsList.add(new MyWaypoint( latitude, longitude));
Log.i("FireBaseTester","latitude = "+latitude+" , longitude = "+longitude);
}
}
}
}
//here you can assign the points to the user
Log.i("FireBaseTester","There are "+userWayPointsList.size()+ " Points for User");
}
@Override
public void onCancelled(FirebaseError firebaseError) {
Log.e("FireBaseTester", "onCancelled - wayPointRef Error is " + firebaseError.getMessage());
}
});
}
};
mRecyclerView.setAdapter(mAdapter);
}
private void loadLoginView() {
Intent intent = new Intent(this, LoginActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
}
致命异常：main process：com.example.rasmusjosefsson.rjcar,pid：19134 com.firebase.client.firebaseException：在com.firebase.ui.firebaserecycleradapter.parsesnapshot（firebaseecycleradapter.java:161)com.firebase.ui.firebaseecycleradapter.getvalue（datasnapshot.java:185)在port.v7.widget.recyclerview$adapter.onbindviewholder(recycerview.java:5471)在Android.support.v7.widget.recyclerview$adapter.bindviewholder(recycerview.java:5504)在Android.support.v7.widget.recyclerview$recycer.getviewforposition(recycerview.java:4741)在Android.support.v7.widget.recyclerview.java:4741)在.LinearLayoutManager.LayoutcAndroid.support.v7.widget.linearlayoutmanager.java:1390)在Android.support.v7.widget.linearlayoutmanager.fill（Linearlayoutmanager.java:1353)在Android.support.v7.widget.linearlayoutmanager.onlayoutchildren（Linearlayoutmanager.java:1374)在Android.support.v7.widget.linearlayoutmanager.onlayoutchildren（view.layout（view.java:16630)在Android.view.viewgroup.layout（viewgroup.java:5437)在Android.support.design.widget.headerscrollingviewBehavior.layoutchild（headerscrollingviewBehavior.java:122)在Android.support.design.widget.viewoffsetBehavior.java:122)在16630）在Android.view.viewgroup.layout（viewgroup.java:5437)在Android.widget.framelayout.layoutchildren（framelayout.java:336)在Android.widget.framelayout.onlayout（framelayout.java:273)在Android.view.view.viewgroup.layout（view.java:16630)在Android.view.view.viewgroup.layout（view.java:5437)在：1495）在Android.view.view.layout（view.java:16630)在Android.view.viewgroup.layout（viewgroup.java:5437)在Android.widget.framelayout.layoutchildren（framelayout.java:336)在Android.widget.framelayout.onlayout（framelayout.java:273)在Android.view.viewgroup.layout（view.java:16630)在Android.view.viewgroup.layout（在Android.widget.linearlayout.onLayout（LinearLayout.java:1495)在Android.view.view.layout（view.java:16630)在Android.view.viewgroup.layout（viewgroup.java:5437)在Android.widget.framelayout.layoutchildren（framelayout.java:336)在Android.widget.framelayout.onlayout（framelayout.java:273)在com.Android.internal.policy.phoneWindow$decorview.java:2678)在pl.java:2171)在Android.view.viewrootimpl.performtraversals（viewrootimpl.java:1931)在Android.view.viewrootimpl.doTraversal（viewrootimpl.java:1107)在Android.view.viewrootimpl.java:1107)，在Android.view.viewrootimpl.run（viewrootimpl.java:6013)，在Android.view.choreographer$callbackrecord.run（choreographer.java:858)，在$FrameDisplayEventReceiver.run（choreographer.java:844)在Android上。OS.H
共有1个答案
更新后的答案将Firebase URL更改为最终字符串userUrl=constants.firebase_url+“/users”（去掉URL的其余部分）。我在这段新代码中所做的是遍历数据，并为每个lat-lon对创建MyWayPoint实例。我在代码中指出了您可以从哪里开始使用MyWayPoint来执行您想要的任何操作：
userRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Log.i("FireBaseTester", "onDataChange()");
if (dataSnapshot.getChildrenCount() > 0) {
Log.i("FireBaseTester", "There are "+dataSnapshot.getChildrenCount()+" Users");
for (DataSnapshot userSnapshot : dataSnapshot.getChildren()) {
String email = null;
if(userSnapshot.child("email") != null) {
//this is how you get the value of Email
email = userSnapshot.child("email").getValue().toString();
Log.i("FireBaseTester", "User Email:"+email+" PLAIN");
}
if(userSnapshot.child("waypoints") !=null){
if(userSnapshot.child("waypoints").getChildrenCount() > 0){
Firebase wayPointRef = userSnapshot.child("waypoints").getRef();
if(wayPointRef != null){
wayPointRef.addValueEventListener(new ValueEventListener() {
//this keeps per-user list of points
List<MyWaypoint> userWayPointsList = new ArrayList<MyWaypoint>();
@Override
public void onDataChange(DataSnapshot wayPointsDataSnapshot) {
if(wayPointsDataSnapshot.getChildrenCount() > 0){
for (DataSnapshot wayPointsSnapshotChild : wayPointsDataSnapshot.getChildren()){
Log.i("FireBaseTester", "For-Loop :: wayPointsSnapshotChild.getValue() : "+wayPointsSnapshotChild.getValue());
if(wayPointsSnapshotChild.getChildrenCount()>0){
for (DataSnapshot wayPointsChild : wayPointsSnapshotChild.getChildren()){
//this is where we get the Lat and Lon
double latitude = Double.parseDouble(wayPointsChild.child("latitude").getValue().toString());
double longitude = Double.parseDouble(wayPointsChild.child("longitude").getValue().toString());
userWayPointsList.add(new MyWaypoint( latitude, longitude));
Log.i("FireBaseTester","latitude = "+latitude+" , longitude = "+longitude);
}
}
}
}
//here you can assign the points to the user
Log.i("FireBaseTester","There are "+userWayPointsList.size()+ " Points for User");
}
@Override
public void onCancelled(FirebaseError firebaseError) {
Log.e("FireBaseTester", "onCancelled - wayPointRef Error is " + firebaseError.getMessage());
}
});
}
}
else{
Log.i("FireBaseTester", "No WayPoints Data Received");
}
}
}
}
else{
//no data?
Log.i("FireBaseTester", "No Data Received");
}
}
@Override
public void onCancelled(FirebaseError firebaseError) {
Log.e("FireBaseTester", "onCancelled - Error is "+firebaseError.getMessage());
}
});
最新更新：您表示您更喜欢检索特定于用户的数据，而不是所有用户的列表（就像我在上面的代码中建议的那样）。下面是用户特定数据的代码。您的URL现在应该类似于:最终字符串userUrl=constants.firebase_url+“/users/”+muserid；
userRef.myFirebaseRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.getChildrenCount() > 0) {
Log.i("FireBaseTester", "There are "+dataSnapshot.getChildrenCount()+" User Attributes");
String email = null;
if(dataSnapshot.child("email") != null) {
//this is how you get the value of Email
email = dataSnapshot.child("email").getValue().toString();
Log.i("FireBaseTester", "User Email:"+email+" PLAIN");
}
if(dataSnapshot.child("waypoints") !=null){
if(dataSnapshot.child("waypoints").getChildrenCount() > 0){
Firebase wayPointRef = dataSnapshot.child("waypoints").getRef();
if(wayPointRef != null){
wayPointRef.addValueEventListener(new ValueEventListener() {
//this keeps per-user list of points
List<MyWaypoint> userWayPointsList = new ArrayList<MyWaypoint>();
@Override
public void onDataChange(DataSnapshot wayPointsDataSnapshot) {
if(wayPointsDataSnapshot.getChildrenCount() > 0){
for (DataSnapshot wayPointsSnapshotChild : wayPointsDataSnapshot.getChildren()){
Log.i("FireBaseTester", "For-Loop :: wayPointsSnapshotChild.getValue() : "+wayPointsSnapshotChild.getValue());
if(wayPointsSnapshotChild.getChildrenCount()>0){
for (DataSnapshot wayPointsChild : wayPointsSnapshotChild.getChildren()){
//this is where we get the Lat and Lon
double latitude = Double.parseDouble(wayPointsChild.child("latitude").getValue().toString());
double longitude = Double.parseDouble(wayPointsChild.child("longitude").getValue().toString());
userWayPointsList.add(new MyWaypoint( latitude, longitude));
Log.i("FireBaseTester","latitude = "+latitude+" , longitude = "+longitude);
}
}
}
}
//here you can assign the points to the user
Log.i("FireBaseTester","There are "+userWayPointsList.size()+ " Points for User");
}
@Override
public void onCancelled(FirebaseError firebaseError) {
Log.e("FireBaseTester", "onCancelled - wayPointRef Error is " + firebaseError.getMessage());
}
});
}
}
else{
Log.i("FireBaseTester", "No WayPoints Data Received");
}
}
}
else{
//no data?
Log.i("FireBaseTester", "No User Attributes");
}
}
@Override
public void onCancelled(FirebaseError firebaseError) {
Log.e("FireBaseTester", "onCancelled - Error is "+firebaseError.getMessage());
}
});
我希望这能让你轻松些。顺便说一下，向您展示使用RecycerView的代码将非常有用--在这种情况下，您可能希望在这里查看一个很好的示例。
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