我正在制作Expandable RecyclerView。问题是我在ArrayList中有数据但是适配器没有设置。
我试过在 arrayListNotiTypes.add之后设置适配器（新的NotiTypes（“关于SMS”，addNotiToParticularNotiType（jaSms，“”）））; 这一行，但是发生了同样的错误。我为不同的模块制作了这种可扩展的RecyclerView。它工作得很好。
以下是我的尝试..
Notification_Activity.java
public class Notification_Activity extends AppCompatActivity {
// Widgets
private ProgressDialog progressDialog;
private RecyclerView recyclerView_Noti;
// Variables
private String url = "notification.php";
private ArrayList<NotiTypes> arrayListNotiTypes;
private ArrayList<ActualNotis> arrayListActualNotis;
// Others
private AdapterNotification adapterNoti;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_notification);
find_view_by_id();
init();
if (Commom_Methods.isNetworkAvailable(this)) {
fetchData();
} else {
Toast.makeText(this, "Please, Coonect to internet!!", Toast.LENGTH_SHORT).show();
}
// Setting Adapter for Notification
adapterNoti = new AdapterNotification(Notification_Activity.this, arrayListNotiTypes);
recyclerView_Noti.setAdapter(adapterNoti);
recyclerView_Noti.setLayoutManager(new LinearLayoutManager(Notification_Activity.this));
}
private void find_view_by_id() {
recyclerView_Noti = (RecyclerView) findViewById(R.id.recycle_noti);
}
private void init() {
arrayListNotiTypes = new ArrayList<>();
}
private void fetchData() {
StringRequest stringReq = new StringRequest(Request.Method.POST, Constants.base_url + url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.e("onResponse: ", response);
progressDialog.dismiss();
if (response != null) {
try {
JSONObject jo = new JSONObject(response);
if (jo.has("success")) {
JSONObject joNoti = jo.getJSONObject("notification");
/*JSONArray jaStu = joNoti.getJSONArray("noti_student");
arrayListNotiTypes.add(new NotiTypes("About Student", addNotiToParticularNotiType(jaStu, "")));*/
JSONArray jaBatch = joNoti.getJSONArray("noti_batch");
arrayListNotiTypes.add(new NotiTypes("About Batch", addNotiToParticularNotiType(jaBatch, "")));
JSONArray jaInst = joNoti.getJSONArray("noti_institute");
arrayListNotiTypes.add(new NotiTypes("About Institute", addNotiToParticularNotiType(jaInst, "attach")));
JSONArray jaFee = joNoti.getJSONArray("noti_fee");
arrayListNotiTypes.add(new NotiTypes("About Fees", addNotiToParticularNotiType(jaFee, "attach")));
JSONArray jaSms = joNoti.getJSONArray("noti_sms");
arrayListNotiTypes.add(new NotiTypes("About SMS", addNotiToParticularNotiType(jaSms, "")));
} else {
Toast.makeText(getApplicationContext(), jo.getString("error_msg"), Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Toast.makeText(getApplicationContext(), "Server error! Don't get Data from server. Try again later.", Toast.LENGTH_LONG).show();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), "Error:" + error.getMessage(), Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put("id", Preferences.readString(getApplicationContext(), Preferences.KEY_SL_ID, ""));
params.put("tution_center_sl", Preferences.readString(getApplicationContext(), Preferences.KEY_TUTION_CENTER_SL, ""));
params.put("batch_sl", Preferences.readString(getApplicationContext(), Preferences.KEY_BATCH_SL, ""));
params.put("batch_grup_sl", Preferences.readString(getApplicationContext(), Preferences.KEY_BATCH_GRUP_SL, ""));
params.put("co_sl", Preferences.readString(getApplicationContext(), Preferences.KEY_CO_SL, ""));
params.put("drange_sl", Preferences.readString(getApplicationContext(), Preferences.KEY_DRANGE_SL, ""));
return params;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<String, String>();
headers.put("X-Apikey", Preferences.readString(getApplicationContext(), Preferences.KEY_USER_XAPIKEY, ""));
return headers;
}
};
RequestQueue queue = Volley.newRequestQueue(this);
queue.add(stringReq);
progressDialog = new ProgressDialog(this);
progressDialog.setMessage("Loading...");
progressDialog.show();
}
private ArrayList<ActualNotis> addNotiToParticularNotiType(JSONArray jsonArray, String attachments) throws JSONException {
arrayListActualNotis = new ArrayList<>();
if (jsonArray.length() > 0) {
for (int j = 0; j < jsonArray.length(); j++) {
JSONObject joInner = jsonArray.getJSONObject(j);
String notiTitle = joInner.getString("title");
String notiDesc = joInner.getString("decription");
String attach = "";
if (!attachments.equals(""))
attach = joInner.getString("attach");
arrayListActualNotis.add(new ActualNotis(notiTitle, notiDesc, attach));
}
} else {
arrayListActualNotis.add(new ActualNotis("No Notifications!!", "", ""));
}
return arrayListActualNotis;
}
}
AdapterNotification.java
public class AdapterNotification extends ExpandableRecyclerViewAdapter<AdapterNotification.NotiTypesViewHolder, AdapterNotification.ActualNotisViewHolder> {
private Activity mActivity;
public AdapterNotification(Activity activity, List<? extends ExpandableGroup> groups) {
super(groups);
this.mActivity = activity;
}
@Override
public NotiTypesViewHolder onCreateGroupViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = (LayoutInflater) mActivity.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.noti_type_group_view_holder, parent, false);
return new NotiTypesViewHolder(view);
}
@Override
public ActualNotisViewHolder onCreateChildViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = (LayoutInflater) mActivity.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.actual_notis_child_view_holder, parent, false);
return new ActualNotisViewHolder(view);
}
@Override
public void onBindGroupViewHolder(NotiTypesViewHolder holder, int flatPosition, ExpandableGroup group) {
holder.setGroupName(group);
}
@Override
public void onBindChildViewHolder(ActualNotisViewHolder holder, int flatPosition, ExpandableGroup group, int childIndex) {
final ActualNotis notis = ((NotiTypes) group).getItems().get(childIndex);
holder.onBind(notis, group);
}
public class NotiTypesViewHolder extends GroupViewHolder {
private TextView txt_noti_type;
public NotiTypesViewHolder(View itemView) {
super(itemView);
txt_noti_type = (TextView) itemView.findViewById(R.id.txt_noti_type);
}
@Override
public void expand() {
txt_noti_type.setCompoundDrawablesWithIntrinsicBounds(0, 0, R.drawable.up_arrow, 0);
Log.e("Adapter", "Expand");
}
@Override
public void collapse() {
txt_noti_type.setCompoundDrawablesWithIntrinsicBounds(0, 0, R.drawable.down_arrow, 0);
Log.e("Adapter", "collapse");
}
public void setGroupName(ExpandableGroup group) {
txt_noti_type.setText(group.getTitle());
}
}
public class ActualNotisViewHolder extends ChildViewHolder {
private TextView txt_noti, txt_noti_desc;
public ActualNotisViewHolder(View itemView) {
super(itemView);
txt_noti = (TextView) itemView.findViewById(R.id.txt_noti);
txt_noti_desc = (TextView) itemView.findViewById(R.id.txt_noti_desc);
}
public void onBind(ActualNotis actualNotis, ExpandableGroup group) {
switch (actualNotis.getmNotiTitle()) {
case "noti_student":
txt_noti.setText(actualNotis.getmNotiTitle());
txt_noti_desc.setText(actualNotis.getmNotiDesc());
break;
case "noti_batch":
txt_noti.setText(actualNotis.getmNotiTitle());
txt_noti_desc.setText(actualNotis.getmNotiDesc());
break;
case "noti_institute":
txt_noti.setText(actualNotis.getmNotiTitle());
txt_noti_desc.setText(actualNotis.getmNotiDesc());
break;
case "noti_fee":
txt_noti.setText(actualNotis.getmNotiTitle());
txt_noti_desc.setText(actualNotis.getmNotiDesc());
break;
case "noti_sms":
txt_noti.setText(actualNotis.getmNotiTitle());
txt_noti_desc.setText(actualNotis.getmNotiDesc());
break;
default:
break;
}
}
}
}
来自服务器的JSON响应
{
"notification": {
"noti_batch": [
{
"title": "testtest",
"decription": "testtest"
}
],
"noti_institute": [
{
"title": "test",
"decription": "testtest",
"attach": ""
}
],
"noti_fee": [
{
"title": "test",
"decription": "test",
"attach": ""
}
],
"noti_sms": [
{
"title": "2016-11-03 00:00:00",
"decription": ""
}
]
},
"success": true
}
提前致谢！
答案 0 :(得分：2)
setAdapter，即onResponse（）内部或者您必须在更改List中的数据后通知适配器