Question

当点击某个项目时，我有一个带有列表的应用程序打开一个可滚动的界面，里面有一个片段。没有加载片段应用程序工作正常，但当我想加载片段它停止。

DiveDetailsFragment.Java

 package be.gillescoeman.scubajournal;

 import android.content.Context;
 import android.net.Uri;
 import android.os.Bundle;
 // import android.app.Fragment;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;


 /**
  * A simple {@link Fragment} subclass.
  * Activities that contain this fragment must implement the
  * {@link DiveDetailsFragment.OnFragmentInteractionListener} interface
  * to handle interaction events.
  * Use the {@link DiveDetailsFragment#newInstance} factory method to
  * create an instance of this fragment.
  */
 public class DiveDetailsFragment extends Fragment {
     private OnFragmentInteractionListener mListener;

     public DiveDetailsFragment() {
         // Required empty public constructor
     }

     public static DiveDetailsFragment newInstance() {
         DiveDetailsFragment fragment = new DiveDetailsFragment();
         return fragment;
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
     }

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
         // Inflate the layout for this fragment
         return inflater.inflate(R.layout.fragment_dive_details, container, false);
     }

     public void onButtonPressed(Uri uri) {
         if (mListener != null) {
             mListener.onFragmentInteraction(uri);
         }
     }

     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
         if (context instanceof OnFragmentInteractionListener) {
             mListener = (OnFragmentInteractionListener) context;
         } else {
             throw new RuntimeException(context.toString()
                     + " must implement OnFragmentInteractionListener");
         }
     }

     @Override
     public void onDetach() {
         super.onDetach();
         mListener = null;
     }

     public interface OnFragmentInteractionListener {
         // TODO: Update argument type and name
         void onFragmentInteraction(Uri uri);
     }
 }

DiveDetailsActivity.Java

 package be.gillescoeman.scubajournal;

 // import android.app.Fragment;
 // import android.app.FragmentTransaction;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentManager;
 import android.os.Bundle;
 import android.support.design.widget.FloatingActionButton;
 import android.support.design.widget.Snackbar;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.widget.Toolbar;
 import android.view.View;

 public class DiveDetailsActivity extends AppCompatActivity {

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_dive_details);
         Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
         setSupportActionBar(toolbar);

 //        FragmentTransaction ft = getFragmentManager().beginTransaction();
 //        Fragment diveDetailsFragment = DiveDetailsFragment.newInstance();
 //        ft.add(R.id.diveDetailsFragmentContainer, diveDetailsFragment);
 //        ft.commit();

         FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
         fab.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
                 Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                         .setAction("Action", null).show();
             }
         });

 //        if (savedInstanceState == null) {
 //            getSupportFragmentManager()
 //                    .beginTransaction()
 //                    .add(R.id.diveDetailsFragmentContainer, DiveDetailsFragment.newInstance(), "DiveDetails")
 //                    .commit();
 //        }

         if (findViewById(R.id.diveDetailsFragmentContainer) != null) {
             if (savedInstanceState != null) {
                 return;
             }

             // Create an instance of AddServerFragment
             DiveDetailsFragment fragment = new DiveDetailsFragment();

             // Add the fragment to the 'fragment_container' FrameLayout
             getSupportFragmentManager().beginTransaction()
                     .add(R.id.diveDetailsFragmentContainer, fragment).commit();
         }
     }
 }

fragment_dive_details.xml

 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     tools:context="be.gillescoeman.scubajournal.DiveDetailsFragment"
     class="be.gillescoeman.scubajournal.DiveDetailsFragment">

     <!-- TODO: Update blank fragment layout -->
     <TextView
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:text="@string/hello_blank_fragment" />

     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_margin="@dimen/text_margin"
         android:text="@string/large_text" />

 </FrameLayout>

content_dive_details.xml

 <?xml version="1.0" encoding="utf-8"?>
 <android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     app:layout_behavior="@string/appbar_scrolling_view_behavior"
     tools:context="be.gillescoeman.scubajournal.DiveDetailsActivity"
     tools:showIn="@layout/activity_dive_details">

     <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
         android:id="@+id/diveDetailsFragmentContainer"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content" />

 </android.support.v4.widget.NestedScrollView>

activity_dive_detail.xml

 <?xml version="1.0" encoding="utf-8"?>
 <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
     tools:context="be.gillescoeman.scubajournal.DiveDetailsActivity">

     <android.support.design.widget.AppBarLayout
         android:id="@+id/app_bar"
         android:layout_width="match_parent"
         android:layout_height="@dimen/app_bar_height"
         android:fitsSystemWindows="true"
         android:theme="@style/AppTheme.AppBarOverlay">

         <android.support.design.widget.CollapsingToolbarLayout
             android:id="@+id/toolbar_layout"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:fitsSystemWindows="true"
             app:contentScrim="?attr/colorPrimary"
             app:layout_scrollFlags="scroll|exitUntilCollapsed">

             <android.support.v7.widget.Toolbar
                 android:id="@+id/toolbar"
                 android:layout_width="match_parent"
                 android:layout_height="?attr/actionBarSize"
                 app:layout_collapseMode="pin"
                 app:popupTheme="@style/AppTheme.PopupOverlay" />

         </android.support.design.widget.CollapsingToolbarLayout>
     </android.support.design.widget.AppBarLayout>

     <include layout="@layout/content_dive_details" />

     <android.support.design.widget.FloatingActionButton
         android:id="@+id/fab"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_margin="@dimen/fab_margin"
         app:layout_anchor="@id/app_bar"
         app:layout_anchorGravity="bottom|end"
         app:srcCompat="@android:drawable/ic_dialog_email" />

 </android.support.design.widget.CoordinatorLayout>

Android监控日志

05-03 13:08:55.049 16815-16815/? I/art: Not late-enabling -Xcheck:jni (already on) 
05-03 13:08:55.049 16815-16815/? W/art: Unexpected CPU variant for X86 using defaults: x86 
05-03 13:08:55.189 16815-16815/be.gillescoeman.scubajournal W/System: ClassLoader referenced unknown path: /data/app/be.gillescoeman.scubajournal-2/lib/x86 
05-03 13:08:55.198 16815-16815/be.gillescoeman.scubajournal I/InstantRun: starting instant run server: is main process 
05-03 13:08:55.254 16815-16815/be.gillescoeman.scubajournal W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable 
05-03 13:08:55.609 16815-16822/be.gillescoeman.scubajournal W/art: Suspending all threads took: 13.168ms 
05-03 13:08:55.859 16815-16843/be.gillescoeman.scubajournal I/OpenGLRenderer: Initialized EGL, version 1.4 
05-03 13:08:55.859 16815-16843/be.gillescoeman.scubajournal D/OpenGLRenderer: Swap behavior 1 
05-03 13:08:55.859 16815-16843/be.gillescoeman.scubajournal W/OpenGLRenderer: Failed to choose config with EGL_SWAP_BEHAVIOR_PRESERVED, retrying without... 
05-03 13:08:55.859 16815-16843/be.gillescoeman.scubajournal D/OpenGLRenderer: Swap behavior 0 
05-03 13:08:55.965 16815-16815/be.gillescoeman.scubajournal W/art: Before Android 4.1, method int android.support.v7.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView 
05-03 13:09:00.502 16815-16815/be.gillescoeman.scubajournal D/AndroidRuntime: Shutting down VM

--------- beginning of crash 05-03 13:09:00.502 16815-16815/be.gillescoeman.scubajournal E/AndroidRuntime: FATAL EXCEPTION: main
  Process: be.gillescoeman.scubajournal, PID: 16815
  java.lang.RuntimeException: Unable to start activity ComponentInfo{be.gillescoeman.scubajournal/be.gillescoeman.scubajournal.DiveDetailsActivity}: java.lang.RuntimeException: be.gillescoeman.scubajournal.DiveDetailsActivity@18ae9d9 must implement OnFragmentInteractionListener
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2665)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726)
  at android.app.ActivityThread.-wrap12(ActivityThread.java)
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477)
  at android.os.Handler.dispatchMessage(Handler.java:102)
  at android.os.Looper.loop(Looper.java:154)
  at android.app.ActivityThread.main(ActivityThread.java:6119)
  at java.lang.reflect.Method.invoke(Native Method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: java.lang.RuntimeException: be.gillescoeman.scubajournal.DiveDetailsActivity@18ae9d9 must implement OnFragmentInteractionListener
  at be.gillescoeman.scubajournal.DiveDetailsFragment.onAttach(DiveDetailsFragment.java:57)
  at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1231)
  at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1085)
  at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:976)
  at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:95)
  at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2146)
  at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2103)
  at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2013)
  at android.support.v4.app.FragmentController.execPendingActions(FragmentController.java:388)
  at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:607)
  at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:178)
  at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1248)
  at android.app.Activity.performStart(Activity.java:6696)
  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2628)
  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2726) 
  at android.app.ActivityThread.-wrap12(ActivityThread.java) 
  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1477) 
  at android.os.Handler.dispatchMessage(Handler.java:102) 
  at android.os.Looper.loop(Looper.java:154) 
  at android.app.ActivityThread.main(ActivityThread.java:6119) 
  at java.lang.reflect.Method.invoke(Native Method) 
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

Answer 1

Fragment中的以下行假定其附加的活动将实现OnFragmentInteractionListener界面。

mListener = (OnFragmentInteractionListener) context;

您需要更改：

public class DiveDetailsActivity extends AppCompatActivity {

为：

public class DiveDetailsActivity extends AppCompatActivity implements OnFragmentInteractionListener {

并实现OnFragmentInteractionListener中的所有抽象方法，这些方法可能是空白的，但对于这个问题来说无关紧要。

Answer 2

实际上删除onAttach()和onDetach()方法似乎可以解决问题

打开片段时Android应用停止

2 个答案: