Android Cardview和回收器截击错误
我有一些代码可以将JSON数据解析到cardview和recycler。我想在片段中显示json数据。我得到了错误，但我不知道是什么原因造成的。任何人都可以帮我 这是我的片段Android Cardview和回收器截击错误,android,json,android-recyclerview,android-volley,android-cardview,Android,Json,Android Recyclerview,Android Volley,Android Cardview,我有一些代码可以将JSON数据解析到cardview和recycler。我想在片段中显示json数据。我得到了错误，但我不知道是什么原因造成的。任何人都可以帮我 这是我的片段 public class HomeFragment extends android.support.v4.app.Fragment { private static final String TAG = HomeActivity.class.getSimpleName(); private ArrayList<
public class HomeFragment extends android.support.v4.app.Fragment {
private static final String TAG = HomeActivity.class.getSimpleName();
private ArrayList<ListItem> listItems;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
ParseData();
RecyclerView recyclerView = (RecyclerView) getActivity().findViewById(R.id.recycler_list);
recyclerView.setHasFixedSize(true);
recyclerView.setAdapter(new ListCardAdapter(listItems, R.layout.report_list_item));
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerView.setLayoutManager(new GridLayoutManager(getActivity(),2));
recyclerView.setItemAnimator(new DefaultItemAnimator());
// Inflate the layout for this fragment
return rootView;
}
private void ParseData(){
JsonArrayRequest listReq = new JsonArrayRequest(AppConfig.URL_LIST,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
ListItem listItem = new ListItem();
listItem.setDesc(obj.getString("desc"));
String image = obj.isNull("image") ? null : obj.getString("image");
listItem.setImge(image);
// adding movie to movies array
listItems.add(listItem);
} catch (JSONException e) {
e.printStackTrace();
}
}
ListCardAdapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
// Adding request to request queue
VolleyController.getInstance().addToRequestQueue(listReq);
}
您可以参考我下面的示例代码。我已经测试过了
public class RecycleCardActivityFragment extends Fragment {
private final List<Person> mPersonList = new ArrayList<>();
public RecycleCardActivityFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_recycle_card, container, false);
Context context = getActivity();
RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.recycleView);
recyclerView.setHasFixedSize(true);
LinearLayoutManager layoutManager = new LinearLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);
final RVAdapter rvAdapter = new RVAdapter(mPersonList);
recyclerView.setAdapter(rvAdapter);
RequestQueue requestQueue = Volley.newRequestQueue(context);
String url = "http://192.16.1.100/api/persons";
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
try {
if (response.length() > 0) {
mPersonList.clear();
for (int i = 0; i < response.length(); i++) {
JSONObject jsonObject = response.getJSONObject(i);
Person person = new Person();
if (!jsonObject.isNull("name")) {
person.name = jsonObject.getString("name");
}
if (!jsonObject.isNull("age")) {
person.age = jsonObject.getInt("age");
}
mPersonList.add(i, person);
}
rvAdapter.notifyDataSetChanged();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("VOLLEY", error.toString());
}
});
requestQueue.add(jsonArrayRequest);
return view;
}
}
公共类RecycleCardActivityFragment扩展了片段{
私有最终列表mPersonList=newarraylist（）；
公共RecycleCardActivityFragment（）{
}
@凌驾
创建视图上的公共视图（布局、充气机、视图组容器、，
Bundle savedInstanceState）{
视图=充气机。充气（R.layout.fragment\u recycle\u卡，容器，假）；
Context=getActivity（）；
recycleView recycleView=（recycleView）view.findViewById（R.id.recycleView）；
recyclerView.setHasFixedSize（true）；
LinearLayoutManager layoutManager=新的LinearLayoutManager（上下文）；
recyclerView.setLayoutManager（layoutManager）；
最终RVAdapter RVAdapter=新RVAdapter（mPersonList）；
recyclerView.setAdapter（rvAdapter）；
RequestQueue RequestQueue=Volley.newRequestQueue（上下文）；
字符串url=”http://192.16.1.100/api/persons";
JsonArrayRequest JsonArrayRequest=newjsonarrayrequest（url，new Response.Listener（））{
@凌驾
公共void onResponse（JSONArray响应）{
试一试{
if（response.length（）>0）{
mPersonList.clear（）；
对于（int i=0；iPersonRVAdapter希望这有帮助 试试看。希望这有帮助！如果它对你有效，我会发布你问题的答案。谢谢@BNK。但在片段中不起作用。我怎么能把它弄成碎片呢？很高兴它能帮你！
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.company.report/com.company.report.activity.HomeActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at id.co.aascenter.suarawarga.activity.HomeFragment.onCreateView(HomeFragment.java:126)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1789)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:955)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1138)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:740)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1501)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:551)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1133)
at android.app.Activity.performStart(Activity.java:4475)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1929)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
at android.app.ActivityThread.access$600(ActivityThread.java:123)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4424)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
at dalvik.system.NativeStart.main(Native Method)
public class RecycleCardActivityFragment extends Fragment {
private final List<Person> mPersonList = new ArrayList<>();
public RecycleCardActivityFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_recycle_card, container, false);
Context context = getActivity();
RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.recycleView);
recyclerView.setHasFixedSize(true);
LinearLayoutManager layoutManager = new LinearLayoutManager(context);
recyclerView.setLayoutManager(layoutManager);
final RVAdapter rvAdapter = new RVAdapter(mPersonList);
recyclerView.setAdapter(rvAdapter);
RequestQueue requestQueue = Volley.newRequestQueue(context);
String url = "http://192.16.1.100/api/persons";
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
try {
if (response.length() > 0) {
mPersonList.clear();
for (int i = 0; i < response.length(); i++) {
JSONObject jsonObject = response.getJSONObject(i);
Person person = new Person();
if (!jsonObject.isNull("name")) {
person.name = jsonObject.getString("name");
}
if (!jsonObject.isNull("age")) {
person.age = jsonObject.getInt("age");
}
mPersonList.add(i, person);
}
rvAdapter.notifyDataSetChanged();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e("VOLLEY", error.toString());
}
});
requestQueue.add(jsonArrayRequest);
return view;
}
}