활동이 시작되지 않았습니다. RecyclerView가 비어 있습니다.

Question

현재 Android 앱을 코딩하는 법을 배우고 있습니다. "The Big Nerd Ranch Guide"입니다.

은 내가 CriminalIntent 꽤 유사하다 다른 응용 프로그램을 구축 시작 CriminalIntent 응용 프로그램을 종료한다. (방금 배운 것을 연습하고 싶습니다.)

앱에서 일종의 프로젝트 관리 도구를 설명해야합니다.

다음 문제 : 아무것도 작동하지 않습니다!

앱을 실행하면 빈 화면이 표시됩니다. 전체 프로젝트의 중단 점은 잡히지 않습니다.

시작 활동은 RecyclerView가 포함 된 부분을 포함하는 활동이어야합니다.

public abstract class SingleFragmentActivity extends FragmentActivity{ 

protected abstract Fragment createFragment(); 

@Override 
public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState) { 
    super.onCreate(savedInstanceState, persistentState); 
    setContentView(R.layout.activity_fragment_content); 

    FragmentManager fm = getSupportFragmentManager(); 
    Fragment fragment = fm.findFragmentById(R.id.fragment_container); 

    if (fragment == null) { 
     fragment = createFragment(); 
     fm.beginTransaction() 
       .add(R.id.fragment_container, fragment) 
       .commit(); 
    } 
} 
} 

ProjectListActivity : (시작되어야한다)

public class ProjectListActivity extends SingleFragmentActivity { 

@Override 
protected Fragment createFragment() { 
    return new ProjectListFragment(); 
} 
} 

<activity android:name=".ProjectListActivity"> 
    <intent-filter> 
      <action android:name="android.intent.action.MAIN"/> 
      <category android:name="android.intent.category.LAUNCHER"/> 
    </intent-filter> 
</activity> 
<activity 
     android:name=".ProjectActivity" 
     android:label="@string/app_name" 
     android:theme="@style/AppTheme.NoActionBar"> 
</activity> 

다른 활동을 모두 상속 추상 클래스가있다 :

blank screen

여기 매니페스트 코드입니다

ProjectListFragment :

public class ProjectListFragment extends Fragment { 

private RecyclerView mProjectRecyclerView; 
private ProjectAdapter mAdapter; 

@Nullable 
@Override 
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
    View v = inflater.inflate(R.layout.fragment_project_list, container, false); 

    mProjectRecyclerView = (RecyclerView) v.findViewById(R.id.project_recycler_view); 
    mProjectRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity())); 

    updateUI(); 

    return v; 
} 

private void updateUI() { 
    ProjectLab projectLab = ProjectLab.getInstance(getActivity()); 
    List<Project> projects = projectLab.getProjects(); 

    mAdapter = new ProjectAdapter(projects); 
    mProjectRecyclerView.setAdapter(mAdapter); 
} 




private class ProjectAdapter extends RecyclerView.Adapter<ProjectHolder> { 

    private List<Project> mProjects; 

    public ProjectAdapter(List<Project> projects) { 
     mProjects = projects; 
    } 

    @Override 
    public ProjectHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     LayoutInflater layoutInflater = LayoutInflater.from(getActivity()); 
     View v = layoutInflater.inflate(R.layout.list_item_project, parent, false); 

     return new ProjectHolder(v); 
    } 

    @Override 
    public void onBindViewHolder(ProjectHolder holder, int position) { 
     Project project = mProjects.get(position); 
     holder.bindProject(project); 
    } 

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




private class ProjectHolder extends RecyclerView.ViewHolder { 

    private Project mProject; 
    private TextView mTitleTextView; 
    private TextView mDescriptionTextView; 
    private TextView mDateTextView; 
    private CheckBox mSolvedCheckBox; 

    public ProjectHolder(View itemView) { 
     super(itemView); 

     mTitleTextView = (TextView) 
       itemView.findViewById(R.id.list_item_title_text_View); 

     mDescriptionTextView = (TextView) 
       itemView.findViewById(R.id.list_item_description_text_view); 

     mDateTextView = (TextView) 
       itemView.findViewById(R.id.list_item_date_text_view); 

     mSolvedCheckBox = (CheckBox) 
       itemView.findViewById(R.id.list_item_finished_check_box); 
    } 

    public void bindProject(Project project) { 
     mProject = project; 
     mTitleTextView.setText(mProject.getTitle()); 
     mDescriptionTextView.setText(mProject.getDescription()); 
     mDateTextView.setText(new SimpleDateFormat("EEEE, dd.MM.yyyy").format(mProject.getDate())); 
     mSolvedCheckBox.setChecked(mProject.isFinished()); 
    } 
} 
} 

미안 해요, 난 바보 야합니다. :(

나는 그것을 디버깅 할 수 없습니다

당신이 나를 도울 수 있기를 바랍니다

편집

XML-파일 :..

activity_fragment.xml

<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="com.ndraeger.android.projecttrackstar.ProjectActivity"> 

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

activity_fragment_content.xml :

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

fragment_project_list.xml :

<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android" 
            android:id="@+id/project_recycler_view" 
            android:layout_width="match_parent" 
            android:layout_height="match_parent" /> 

list_item_project.XML은 :

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
      xmlns:tools="http://schemas.android.com/tools" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent"> 
<CheckBox 
    android:id="@+id/list_item_finished_check_box" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentRight="true" 
    android:padding="4dp"/> 
<TextView 
    android:id="@+id/list_item_title_text_View" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_toLeftOf="@id/list_item_finished_check_box" 
    tools:text="Project Title"/> 
<TextView 
    android:id="@+id/list_item_description_text_view" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@id/list_item_title_text_View" 
    android:layout_toLeftOf="@id/list_item_finished_check_box" 
    tools:text="Project Description"/> 
<TextView 
    android:id="@+id/list_item_date_text_view" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_below="@id/list_item_description_text_view" 
    android:layout_toLeftOf="@id/list_item_finished_check_box" 
    tools:text="Project Date"/> 

(닫는 태그 차단, 죄송합니다, 더 좋은 포맷 없습니다) 활동에

Answer 1

을

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

하지

 @Override 
    public void onCreate(Bundle savedInstanceState, PersistableBundle persistentState) { 
     super.onCreate(savedInstanceState, persistentState); 

    } 

시도