Fehler mit RecyclerView in Android

Question

Ich schreibe eine Android-App, die einen benutzerdefinierten Adapter verwendet, den ich mit RecyclerView gemacht habe. Der Adapter funktioniert jedoch gut, wenn ich aus der Tätigkeit Ebene weg, die es nutzt, die App stürzt ab und gibt mir diese Fehlermeldung:

07-22 14:30:41.037 11083-11083/com.epicodus.parkr E/AndroidRuntime: FATAL EXCEPTION: main 
                   Process: com.epicodus.parkr, PID: 11083 
                   java.lang.NoClassDefFoundError: android.support.v7.widget.RecyclerView$SavedState 
                    at android.support.v7.widget.RecyclerView.onSaveInstanceState(RecyclerView.java:1078) 
                    at android.view.View.dispatchSaveInstanceState(View.java:14641) 
                    at android.view.ViewGroup.dispatchFreezeSelfOnly(ViewGroup.java:3175) 
                    at android.support.v7.widget.RecyclerView.dispatchSaveInstanceState(RecyclerView.java:1109) 
                    at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3161) 
                    at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3161) 
                    at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3161) 
                    at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3161) 
                    at android.view.ViewGroup.dispatchSaveInstanceState(ViewGroup.java:3161) 
                    at android.view.View.saveHierarchyState(View.java:14624) 
                    at com.android.internal.policy.impl.PhoneWindow.saveHierarchyState(PhoneWindow.java:2126) 
                    at android.app.Activity.onSaveInstanceState(Activity.java:1456) 
                    at android.support.v4.app.FragmentActivity.onSaveInstanceState(FragmentActivity.java:564) 
                    at android.support.v7.app.AppCompatActivity.onSaveInstanceState(AppCompatActivity.java:502) 
                    at android.app.Activity.performSaveInstanceState(Activity.java:1383) 
                    at android.app.Instrumentation.callActivityOnSaveInstanceState(Instrumentation.java:1286) 
                    at android.app.ActivityThread.callCallActivityOnSaveInstanceState(ActivityThread.java:4473) 
                    at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:3845) 
                    at android.app.ActivityThread.handleStopActivity(ActivityThread.java:3908) 
                    at android.app.ActivityThread.access$1200(ActivityThread.java:177) 
                    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
                    at android.os.Handler.dispatchMessage(Handler.java:102) 
                    at android.os.Looper.loop(Looper.java:145) 
                    at android.app.ActivityThread.main(ActivityThread.java:5942) 
                    at java.lang.reflect.Method.invoke(Native Method) 
                    at java.lang.reflect.Method.invoke(Method.java:372) 
                    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 
                    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) 

Hier ist der Code für die Tätigkeit, die den Adapter verwendet:

package com.epicodus.parkr.ui; 

import android.content.Intent; 
import android.graphics.Typeface; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

import com.epicodus.parkr.Constants; 
import com.epicodus.parkr.R; 
import com.epicodus.parkr.adapters.RentedSpotsAdapter; 
import com.epicodus.parkr.models.Spot; 
import com.google.android.gms.maps.model.LatLng; 
import com.google.firebase.auth.FirebaseAuth; 
import com.google.firebase.database.DataSnapshot; 
import com.google.firebase.database.DatabaseError; 
import com.google.firebase.database.DatabaseReference; 
import com.google.firebase.database.FirebaseDatabase; 
import com.google.firebase.database.ValueEventListener; 

import java.util.ArrayList; 

import butterknife.Bind; 
import butterknife.ButterKnife; 

public class AccountActivity extends AppCompatActivity implements View.OnClickListener { 

private FirebaseAuth mAuth; 
private String uid; 
private DatabaseReference mSpecificUserReference; 
private DatabaseReference mAllSpotsReference; 
private RentedSpotsAdapter mAdapter; 


@Bind(R.id.rentedSpotRecyclerView) RecyclerView mRecyclerView; 
@Bind(R.id.userNameDisplay) TextView mUserNameDisplay; 
@Bind(R.id.headline) TextView mHeadline; 
@Bind(R.id.logOutButton) Button mLogOutButton; 
@Bind(R.id.postSpotButton) Button mPostSpotButton; 
@Bind(R.id.findSpotsButton) Button mFindSpotsButton; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    mAuth = FirebaseAuth.getInstance(); 
    uid = mAuth.getCurrentUser().getUid(); 
    mSpecificUserReference = FirebaseDatabase.getInstance().getReference().child(Constants.FIREBASE_CHILD_USER).child(uid); 
    mAllSpotsReference = FirebaseDatabase.getInstance().getReference().child("spots"); 


    mSpecificUserReference.addValueEventListener(new ValueEventListener() { 

     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      String userName = dataSnapshot.child("fullName").getValue().toString(); 
      mUserNameDisplay.setText(userName); 
     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 

     } 
    }); 

    mSpecificUserReference.child("rentedSpots").addValueEventListener(new ValueEventListener() { 
     ArrayList<Spot> mSpots = new ArrayList<>(); 
     ArrayList<String> spotKeys = new ArrayList<>(); 
     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      for(DataSnapshot spotKeySnapshot : dataSnapshot.getChildren()){ 
       String spotKey = spotKeySnapshot.getValue().toString(); 
       spotKeys.add(spotKey); 
      } 
      mAllSpotsReference.addValueEventListener(new ValueEventListener() { 
       @Override 
       public void onDataChange(DataSnapshot AllSpotsDataSnapshot) { 
        for(DataSnapshot eachSpotSnapshot : AllSpotsDataSnapshot.getChildren()){ 
         String compareSpotId = eachSpotSnapshot.getKey(); 
         for(String eachSpotKey : spotKeys) 
          if(compareSpotId.equals(eachSpotKey)){ 
           String ownerId = eachSpotSnapshot.child("ownerID").getValue().toString(); 
           String address = eachSpotSnapshot.child("address").getValue().toString(); 
           String description = eachSpotSnapshot.child("description").getValue().toString(); 
           Double lat = Double.parseDouble(eachSpotSnapshot.child("latLng").child("latitude").getValue().toString()); 
           Double lng = Double.parseDouble(eachSpotSnapshot.child("latLng").child("longitude").getValue().toString()); 
           LatLng newLatLng = new LatLng(lat, lng); 
           String startDate = eachSpotSnapshot.child("startDate").getValue().toString(); 
           String startTime = eachSpotSnapshot.child("startTime").getValue().toString(); 
           String endDate = eachSpotSnapshot.child("endDate").getValue().toString(); 
           String endTime = eachSpotSnapshot.child("endTime").getValue().toString(); 
           Spot newSpot = new Spot(eachSpotKey, ownerId, address, description, newLatLng, startDate, startTime, endDate, endTime); 
           mSpots.add(newSpot); 
          } 
        } 
        mAdapter = new RentedSpotsAdapter(getApplicationContext(), mSpots); 
        mRecyclerView.setAdapter(mAdapter); 
        RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(AccountActivity.this); 
        mRecyclerView.setLayoutManager(layoutManager); 
        mRecyclerView.setHasFixedSize(true); 
       } 

       @Override 
       public void onCancelled(DatabaseError databaseError) { 
        finish(); 
       } 
      }); 

     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 
      finish(); 
     } 
    }); 


    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_account); 
    ButterKnife.bind(this); 

    Typeface newFont = Typeface.createFromAsset(getAssets(), "fonts/Lobster-Regular.ttf"); 
    mHeadline.setTypeface(newFont); 

    Intent infoIntent = getIntent(); 
    String userName = infoIntent.getStringExtra("user"); 
    mUserNameDisplay.setText(userName); 

    mPostSpotButton.setOnClickListener(this); 
    mLogOutButton.setOnClickListener(this); 
    mFindSpotsButton.setOnClickListener(this); 
} 

private void logout() { 
    FirebaseAuth.getInstance().signOut(); 
    Intent intent = new Intent(AccountActivity.this, MainActivity.class); 
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK); 
    startActivity(intent); 
    finish(); 
} 

@Override 
public void onClick(View view) { 
    if(view == mLogOutButton){ 
     logout(); 
    } else if (view == mPostSpotButton){ 
     Intent postSpotIntent = new Intent (AccountActivity.this, NewSpotActivity.class); 
     startActivity(postSpotIntent); 
    } else if (view == mFindSpotsButton){ 
     Intent findSpotsIntent = new Intent(AccountActivity.this, FindSpotsActivity.class); 
     startActivity(findSpotsIntent); 
    } 
} 
} 

Und hier ist der Code für den Adapter selbst:

package com.epicodus.parkr.adapters; 

import android.content.Context; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.TextView; 

import com.epicodus.parkr.R; 
import com.epicodus.parkr.models.Spot; 

import java.util.ArrayList; 

import butterknife.Bind; 
import butterknife.ButterKnife; 


public class RentedSpotsAdapter extends RecyclerView.Adapter<RentedSpotsAdapter.RentedSpotViewHolder> { 
private ArrayList<Spot> mSpots; 
private Context mContext; 

public RentedSpotsAdapter(Context context, ArrayList<Spot> spots){ 
    mSpots = spots; 
    mContext = context; 
} 

@Override 
public RentedSpotsAdapter.RentedSpotViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.rented_spot_list_item, parent, false); 
    RentedSpotViewHolder viewHolder = new RentedSpotViewHolder(view); 
    return viewHolder; 
} 

@Override 
public void onBindViewHolder(RentedSpotsAdapter.RentedSpotViewHolder holder, int position) { 
    holder.bindSpot(mSpots.get(position)); 
} 

@Override 
public int getItemCount() { 
    return mSpots.size(); 
} 

public class RentedSpotViewHolder extends RecyclerView.ViewHolder { 

    @Bind(R.id.rentedSpotAddressDisplay) TextView mRentedSpotAddressDisplay; 
    @Bind(R.id.rentedSpotEndDateDisplay) TextView mRentedSpotEndDateDisplay; 
    @Bind(R.id.rentedSpotEndTimeDisplay) TextView mRentedSpotEndTimeDisplay; 

    private Context mContext; 

    public RentedSpotViewHolder(View itemView) { 
     super(itemView); 
     ButterKnife.bind(this, itemView); 
     mContext = itemView.getContext(); 
    } 

    public void bindSpot(Spot spot){ 
     mRentedSpotAddressDisplay.setText(spot.getAddress()); 
     mRentedSpotEndDateDisplay.setText(spot.getEndDate()); 
     mRentedSpotEndTimeDisplay.setText(spot.getEndTime()); 
    } 
} 
} 

hier ist die App-Ebene build.gradle Datei:

apply plugin: 'com.android.application' 


android { 
compileSdkVersion 24 
buildToolsVersion "24.0.0" 

defaultConfig { 
    applicationId "com.epicodus.parkr" 
    minSdkVersion 15 
    targetSdkVersion 24 
    versionCode 1 
    versionName "1.0" 
} 
packagingOptions { 
    exclude 'META-INF/DEPENDENCIES.txt' 
    exclude 'META-INF/DEPENDENCIES' 
    exclude 'META-INF/dependencies.txt' 
    exclude 'META-INF/LICENSE.txt' 
    exclude 'META-INF/LICENSE' 
    exclude 'META-INF/license.txt' 
    exclude 'META-INF/LGPL2.1' 
    exclude 'META-INF/NOTICE.txt' 
    exclude 'META-INF/NOTICE' 
    exclude 'META-INF/notice.txt' 
} 
buildTypes { 
    release { 
     minifyEnabled false 
     proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
    } 
} 
} 

dependencies { 
compile fileTree(dir: 'libs', include: ['*.jar']) 
testCompile 'junit:junit:4.12' 
compile 'com.android.support:appcompat-v7:24.0.0' 
compile 'com.jakewharton:butterknife:7.0.1' 
compile 'com.google.firebase:firebase-database:9.0.2' 
compile 'com.firebaseui:firebase-ui-database:0.4.1' 
compile 'com.google.firebase:firebase-auth:9.0.2' 
compile 'com.google.android.gms:play-services:9.0.2' 

compile 'com.android.support:recyclerview-v7:+' 
compile 'com.google.android.gms:play-services-appindexing:9.0.2' 
} 

configurations.all { 
resolutionStrategy { 
    force 'com.android.support:design:23.4.0' 
    force 'com.android.support:support-v4:23.4.0' 
    force 'com.android.support:appcompat-v7:23.4.0' 
} 
} 


apply plugin: 'com.google.gms.google-services' 

aktualisieren

Ich habe es funktioniert. Es sieht so aus, als müsste ich die onSaveInstanceState-Methode einfach überschreiben und sie leer lassen.

Answer 1

Ich rate nur hier .. Können Sie den Code verschieben und sofort nach der oncreate() -Methode platzieren und es erneut versuchen.

super.onCreate (savedInstanceState);

setContentView (R.layout.activity_account);