我尝试使用RecyclerView但是我得到了这个错误。该应用程序总是崩溃试图打开BuscarPachangaMenu。
ERROR：
FATAL EXCEPTION: main
Process: com.example.developer.pachanya, PID: 2210
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.developer.pachanya/com.example.developer.pachanya.BuscarPachangaMenu}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.developer.pachanya.BuscarPachangaMenu.onCreate(BuscarPachangaMenu.java:77)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
cardXML：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:padding="16dp" >
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/info"
android:layout_width="match_parent"
android:layout_height="200dp"
card_view:cardCornerRadius="15dp"
card_view:cardUseCompatPadding="true"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.example.developer.pachanya.BuscarPachangaMenu">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/nombre_pachanga"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="8dp"
android:text="Pachanga"
android:textSize="14sp"
android:layout_alignStart="@+id/fechaB" />
<TextView
android:layout_width="wrap_content"
android:layout_height="30dp"
android:id="@+id/textnombrepach"
android:layout_alignStart="@+id/fecha_pach"
android:layout_below="@+id/nombre_pachanga"
android:layout_toStartOf="@+id/boton_masOpciones" />
<TextView
android:id="@+id/fecha_pach"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="8dp"
android:text="Fecha"
android:layout_alignBottom="@+id/fechaB"
android:layout_marginStart="58dp" />
<TextView
android:layout_width="wrap_content"
android:layout_height="30dp"
android:id="@+id/textfechapach"
android:layout_below="@+id/fecha_pach"
android:layout_alignStart="@+id/textnombrepach"
android:layout_toStartOf="@+id/boton_masOpciones" />
<ImageView
android:id="@+id/boton_masOpciones"
android:layout_width="30dp"
android:layout_height="wrap_content"
android:src="@drawable/usuarios"
android:layout_alignBottom="@+id/textView1numb"
android:layout_toStartOf="@+id/textView1numb" />
<ImageView
android:id="@+id/fechaB"
android:layout_width="40dp"
android:layout_height="40dp"
android:contentDescription="logo calendario"
android:src="@android:drawable/ic_menu_my_calendar"
android:layout_marginTop="55dp"
android:layout_below="@+id/nombre_pachanga" />
<EditText
android:id="@+id/textView1numb"
android:layout_width="50dp"
android:layout_height="20dp"
android:gravity="center"
android:text="20"
android:clickable="false"
android:cursorVisible="false"
android:focusable="false"
android:focusableInTouchMode="false"
android:inputType="number"
android:layout_alignParentEnd="true"
android:layout_marginEnd="38dp"
android:layout_alignParentTop="true"
android:layout_above="@+id/comartirB" />
<ImageView
android:layout_width="30dp"
android:layout_height="wrap_content"
android:id="@+id/comartirB"
android:src="@drawable/compartir"
android:layout_alignBottom="@+id/textfechapach"
android:layout_toEndOf="@+id/boton_masOpciones" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
RecycleXML：
<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"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".BuscarPachangaMenu">
<android.support.v7.widget.RecyclerView
android:id="@+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
/>
</RelativeLayout>
BuscarPachangaMenu：
public class BuscarPachangaMenu extends AppCompatActivity
implements NavigationView.OnNavigationItemSelectedListener {
ImageView retroceder, siguiente;
Intent intent;
Context context;
private static RecyclerView.Adapter adapter;
private RecyclerView.LayoutManager layoutManager;
private static ArrayList<PachangaModel> data;
private static RecyclerView recyclerView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_buscar_pachanga_menu);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
recyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
try {
BufferedReader mostrarD = new BufferedReader(new InputStreamReader(openFileInput("pachangas.txt")));
String[] nameArray = null;
String[] numJArray = null;
String[] fechArray = null;
String[] lugArray = null;
String[] desArray = null;
String[] motArray = null;
int i = 0;
String nomb = mostrarD.readLine();
while (nomb != null) {
String numJ = mostrarD.readLine();
String fech = mostrarD.readLine();
String lug = mostrarD.readLine();
String des = mostrarD.readLine();
String mot = mostrarD.readLine();
nameArray[i]=nomb;
numJArray[i]=numJ;
fechArray[i]=fech;
lugArray[i]=lug;
desArray[i]=des;
motArray[i]=mot;
nomb = mostrarD.readLine();
}
data = new ArrayList<PachangaModel>();
for (int id = 0; id < nameArray.length; id++) {
data.add(new PachangaModel(
nameArray[id],
numJArray[id],
fechArray[id],
lugArray[id],
desArray[id],
motArray[id]
));
}
adapter = new PachangaAdapter(data);
recyclerView.setAdapter(adapter);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
适配器：
public class PachangaAdapter extends RecyclerView.Adapter<PachangaAdapter.MyViewHolder> {
private ArrayList<PachangaModel> dataSet;
public static class MyViewHolder extends RecyclerView.ViewHolder {
TextView textViewNomb;
TextView textViewJugad;
TextView textViewFech;
public MyViewHolder(View itemView) {
super(itemView);
this.textViewNomb = (TextView) itemView.findViewById(R.id.textnombrepach);
this.textViewJugad = (TextView) itemView.findViewById(R.id.textView1numb);
this.textViewFech = (TextView) itemView.findViewById(R.id.textfechapach);
}
}
public PachangaAdapter(ArrayList<PachangaModel> data) {
this.dataSet = data;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.content_buscar_pachanga_menu, parent, false);
MyViewHolder myViewHolder = new MyViewHolder(view);
return myViewHolder;
}
@Override
public void onBindViewHolder(final MyViewHolder holder, final int listPosition) {
TextView textViewNomb = holder.textViewNomb;
TextView textViewJugad = holder.textViewJugad;
TextView textViewFech = holder.textViewFech;
textViewNomb.setText(dataSet.get(listPosition).getNomPach());
textViewJugad.setText(dataSet.get(listPosition).getJug());
textViewFech.setText(dataSet.get(listPosition).getFech());
}
@Override
public int getItemCount() {
return dataSet.size();
}
}
我怎么解决这个???我需要帮助。
spanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspanspan。对不起，这不要留下我的帖子：S
答案 0 :(得分：0)
必须移动回收
<android.support.v7.widget.RecyclerView
android:id="@+id/my_recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbars="vertical"
/>
到活动xml。
将数组更改为Arraylist。
try {
BufferedReader mostrarD = new BufferedReader(new InputStreamReader(openFileInput("pachangas.txt")));
ArrayList<String> nameArray = new ArrayList<String>();
ArrayList<String> numJArray = new ArrayList<String>();
ArrayList<String> fechArray = new ArrayList<String>();
ArrayList<String> lugArray = new ArrayList<String>();
ArrayList<String> desArray = new ArrayList<String>();
ArrayList<String> motArray = new ArrayList<String>();
String nomb = mostrarD.readLine();
while (nomb != null) {
String numJ = mostrarD.readLine();
String fech = mostrarD.readLine();
String lug = mostrarD.readLine();
String des = mostrarD.readLine();
String mot = mostrarD.readLine();
nameArray.add(nomb);
numJArray.add(numJ);
fechArray.add(fech);
lugArray.add(lug);
desArray.add(des);
motArray.add(mot);
nomb = mostrarD.readLine();
}
data = new ArrayList<PachangaModel>();
for (int id = 0; id < nameArray.size(); id++) {
data.add(new PachangaModel(
nameArray.get(id),
numJArray.get(id),
fechArray.get(id),
lugArray.get(id),
desArray.get(id),
motArray.get(id)
));
}
adapter = new PachangaAdapter(data);
rv.setAdapter(adapter);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
这就是我希望能帮助大家的一切。