我正在尝试显示我从服务器获取的一些数据但是我无法在recyclerView中显示所获取的数据。数据有效且解析（JSON解析）运行良好，但我的活动仅显示白屏。
当我运行应用程序与一些虚拟数据应用工作正常，当我尝试设置从服务器解析的数据时问题到了。
这是我的MainClass
public class JSONDataViewer extends AppCompatActivity {
Context context;
// private List<Movie> movieList
private RecyclerView mRecyclerView;
private CustomAdapter mAdapter;
private List<MyData> dataList = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_jsondata_viewer);
this.context = this;
AndroidNetworking.initialize(getApplicationContext());
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
// mRecyclerView.setHasFixedSize(true);
// loadDummyData();
loadData();
Log.e("DataListPopulated", "Data list populated");
mAdapter = new CustomAdapter(dataList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
Log.e("SettingAdapter", "Setting Adapter");
mRecyclerView.setAdapter(mAdapter);
Log.e("AdapterSet", "Adapter Set Success");
}
private void loadDummyData() {
String question = "Question ";
int qNo = 1;
for (int i = 0; i < 10; i++) {
qNo++;
MyData data = new MyData("" + qNo, question + qNo);
Log.e("Question" + " " + qNo,
"\nQuestion id = " + data.getQuestionId() +
" Question text = " + data.getQuestionText());
dataList.add(data);
}
}
private void loadData() {
AndroidNetworking.post("http://www.skafs.com/survey/api/index.php")
.addBodyParameter("tag", "getquestion")
.addBodyParameter("category_id", "2")
.setPriority(Priority.MEDIUM)
.build()
.getAsJSONObject(new JSONObjectRequestListener() {
@Override
public void onResponse(JSONObject response) {
Log.i("LoadingData", "" + "Successful" + response);
Toast.makeText(context, "Response:\n" + "Loading Data" + response,
Toast.LENGTH_LONG).show();
boolean success = response.optBoolean("success");
if (success) {
Log.e("InsideSuccess", "Success = " + success);
try {
JSONArray questions =
response.optJSONArray("questions");
Log.e("Questions", questions.toString());
for (int i = 0; i < questions.length(); i++) {
JSONObject obj = questions.getJSONObject(i);
MyData data = new MyData(
obj.getString("question_id"),
obj.getString("question_text"));
Log.e("Question" + " " + i,
"\nQuestion id = " + data.getQuestionId() +
" Question text = " + data.getQuestionText());
dataList.add(data);
}
Log.e("ListData", "List Size is = "+dataList.size());
} catch (JSONException e) {
e.printStackTrace();
}
}
}
@Override
public void onError(ANError anError) {
anError.printStackTrace();
Log.e("ParsingJSON", "" + "Failed getting json");
}
});
}
}
您可以看到上述代码loadDummyData();和loadData();有两种方法尝试第一种方法没有问题。
我有一些Log语句，显示来自服务器的数据有效，dataList的大小为9。
这是我的数据格式Log
10-17 21:25:25.217 3078-3078/hostflippa.com.opencart_android E/InsideSuccess: Success = true
10-17 21:25:25.219 3078-3078/hostflippa.com.opencart_android E/Questions: [{"question_id":"1","question_text":"License Status","question_type":"radio","options":[{"option_id":"1","option_text":"Valid","option_value":"5"},{"option_id":"2","option_text":"Expired","option_value":"0"},{"option_id":"3","option_text":"Without License","option_value":"0"}]},{"question_id":"2","question_text":"License date of validity","question_type":"editText","options":[]},{"question_id":"3","question_text":"Type of License","question_type":"radio","options":[{"option_id":"4","option_text":"A-Category","option_value":"5"},{"option_id":"5","option_text":"B-Category","option_value":"2"},{"option_id":"6","option_text":"C-Category","option_value":"2"},{"option_id":"7","option_text":"Dispensar","option_value":"1"},{"option_id":"457","option_text":"20\/21","option_value":"1"}]},{"question_id":"4","question_text":"License Ownership","question_type":"radio","options":[{"option_id":"8","option_text":"Individual","option_value":"0"},{"option_id":"9","option_text":"Chain Pharmacy","option_value":"0"},{"option_id":"10","option_text":"Company","option_value":"0"}]},{"question_id":"5","question_text":"License Number","question_type":"editText","options":[]},{"question_id":"6","question_text":"Computerized License No","question_type":"editText","options":[]},{"question_id":"7","question_text":"NTN Present","question_type":"checkbox","options":[{"option_id":"11","option_text":"Yes","option_value":"1"},{"option_id":"12","option_text":"No","option_value":"0"}]},{"question_id":"8","question_text":"NTN No.","question_type":"editText","options":[]},{"question_id":"9","question_text":"Visit Type","question_type":"radio","options":[{"option_id":"13","option_text":"First visit","option_value":"0"},{"option_id":"14","option_text":"Second visit","option_value":"0"}]}]
10-17 21:25:25.219 3078-3078/hostflippa.com.opencart_android E/Question 0: Question id = 1 Question text = License Status
10-17 21:25:25.219 3078-3078/hostflippa.com.opencart_android E/Question 1: Question id = 2 Question text = License date of validity
10-17 21:25:25.220 3078-3078/hostflippa.com.opencart_android E/Question 2: Question id = 3 Question text = Type of License
10-17 21:25:25.220 3078-3078/hostflippa.com.opencart_android E/Question 3: Question id = 4 Question text = License Ownership
10-17 21:25:25.220 3078-3078/hostflippa.com.opencart_android E/Question 4: Question id = 5 Question text = License Number
10-17 21:25:25.220 3078-3078/hostflippa.com.opencart_android E/Question 5: Question id = 6 Question text = Computerized License No
10-17 21:25:25.221 3078-3078/hostflippa.com.opencart_android E/Question 6: Question id = 7 Question text = NTN Present
10-17 21:25:25.221 3078-3078/hostflippa.com.opencart_android E/Question 7: Question id = 8 Question text = NTN No.
10-17 21:25:25.221 3078-3078/hostflippa.com.opencart_android E/Question 8: Question id = 9 Question text = Visit Type
10-17 21:25:25.221 3078-3078/hostflippa.com.opencart_android E/ListData: List Size is = 9
请指出我做错事的方向。
我没有任何异常。这是我的CustomAdapter课程
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.MyViewHolder> {
private List<MyData> dataList;
public CustomAdapter(List<MyData> dataList) {
this.dataList = dataList;
Log.e("Constructor", "Working");
Log.e("Constructor", "DataList Size = " + dataList.size());
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.card_lay, parent, false);
Log.e("LayoutInflated", "Working");
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Log.e("OnBIndMethod", "OnBind Working");
MyData data = dataList.get(position);
holder.questionId.setText(data.getQuestionId());
holder.questionText.setText(data.getQuestionText());
}
@Override
public int getItemCount() {
return dataList.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView questionId, questionText;
public MyViewHolder(View itemView) {
super(itemView);
questionId = (TextView) itemView.findViewById(R.id.question_id);
questionText = (TextView) itemView.findViewById(R.id.question_text);
Log.e("FindViewById", "Working");
}
}
}
MyData类有两个字符串类型及其getter / setter方法。
答案 0 :(得分：3)
for (int i = 0; i < questions.length(); i++) {
JSONObject obj = questions.getJSONObject(i);
MyData data = new MyData(
obj.getString("question_id"),
obj.getString("question_text"));
Log.e("Question" + " " + i,
"\nQuestion id = " + data.getQuestionId() +
" Question text = " + data.getQuestionText());
dataList.add(data);
}
// notify data set change call missing
mAdapter.notifyDataSetChanged();