问题
i trying to connect with themoviedb.orgbut there's some issues
MainActivityFragment.java
public class MainActivityFragment extends Fragment {
public Item[] dataAdapter ;
public MainActivityFragment() {
this.updateData();
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Add this line in order for this fragment to handle menu events.
setHasOptionsMenu(true);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.menu_fragment, menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.refresh_settings) {
startActivity(new Intent(getActivity(),SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
CustomArrayAdapter adapter =new CustomArrayAdapter(this.getActivity() , R.layout.item , dataAdapter);
// Get a reference to the ListView, and attach this adapter to it.
GridView gridView = (GridView) rootView.findViewById(R.id.main_grid_view);
gridView.setAdapter(adapter);
return rootView;
}
private void updateData() {
GetData DataTask = new GetData();
DataTask.execute();
}
@Override
public void onStart() {
super.onStart();
this.updateData();
}
public class GetData extends AsyncTask<Void, Void, Item[]> {
private final String LOG_TAG = GetData.class.getSimpleName();
private Item[] getDataFromJson(String forecastJsonStr)
throws JSONException{
// These are the names of the JSON objects that need to be extracted.
final String RESULTS = "results";
final String IMG_PATH = "poster_path";
final String TITLE = "title";
JSONObject dataJson = new JSONObject(forecastJsonStr);
JSONArray dataArray = dataJson.getJSONArray(RESULTS);
int numofresults = dataArray.length();
Item[] resultStrs = new Item[0];
for(int i = 0; i < numofresults; i++) {
// For now, using the format "Day, description, hi/low"
String img_path;
String title;
JSONObject movieData = dataArray.getJSONObject(i);
img_path = movieData.getString(IMG_PATH);
img_path ="http://image.tmdb.org/t/p/w185"+img_path;
title = movieData.getString(TITLE);
Item element = new Item(img_path,title);
resultStrs[i] = element;
}
return resultStrs;
}
@Override
protected Item[] doInBackground(Void... strings) {
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String dataJsonStr = null;
String parm = getString(R.string.pref_sort_most);
String api_key = "API KEY";
try {
final String BASE_URL =
"http://api.themoviedb.org/3/discover/movie?";
final String QUERY_PARAM = "sort_by";
final String APPID_PARAM = "api_key";
Uri builtUri = Uri.parse(BASE_URL).buildUpon()
.appendQueryParameter(QUERY_PARAM, parm)
.appendQueryParameter(APPID_PARAM, api_key)
.build();
URL url = new URL(builtUri.toString());
// Create the request to themoviedb.org, and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
return null;
}
dataJsonStr = buffer.toString();
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
try {
return getDataFromJson(dataJsonStr);
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Item[] result) {
if (result != null) {
dataAdapter = result;
}
// New data is back from the server. Hooray!
}
}
}
CustomArrayAdapter.java
public class CustomArrayAdapter extends ArrayAdapter<Item> {
Context context;
int resource;
Item objects[] = null;
public CustomArrayAdapter(Context context, int resource, Item[] objects) {
super(context, resource, objects);
this.resource = resource;
this.context = context;
this.objects = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
View row = convertView;
DataHolder holder = null;
if(row == null)
{
row = LayoutInflater.from(getContext()).inflate(
R.layout.item, parent, false);
holder = new DataHolder();
holder.imgIcon = (ImageView)row.findViewById(R.id.image_main_item);
holder.txtTitle = (TextView)row.findViewById(R.id.title_movie);
row.setTag(holder);
}else
{
holder = (DataHolder)row.getTag();
}
Item item = objects[position];
holder.txtTitle.setText(item.title);
Picasso.with(context).load(item.icon).into(holder.imgIcon);
return row;
}
static class DataHolder
{
ImageView imgIcon;
TextView txtTitle;
}
}
Item.java
public class Item {
public String icon;
public String title;
public Item(){
super();
}
public Item(String icon, String title) {
super();
this.icon = icon;
this.title = title;
}
}
and here my Logcat
12-23 15:06:40.832 1644-1644/com.example.mohamed.movieapp E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: com.example.mohamed.movieapp, PID: 1644 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.mohamed.movieapp/com.example.mohamed.movieapp.MainActivity}: android.view.InflateException: Binary XML file line #1: Error inflating class fragment at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5254) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) Caused by: android.view.InflateException: Binary XML file line #1: Error inflating class fragment at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:763) at android.view.LayoutInflater.inflate(LayoutInflater.java:482) at android.view.LayoutInflater.inflate(LayoutInflater.java:414) at android.view.LayoutInflater.inflate(LayoutInflater.java:365) at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256) at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109) at com.example.mohamed.movieapp.MainActivity.onCreate(MainActivity.java:19) at android.app.Activity.performCreate(Activity.java:5990) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5254) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) Caused by: java.lang.NullPointerException: storage == null at java.util.Arrays$ArrayList.(Arrays.java:38) at java.util.Arrays.asList(Arrays.java:155) at android.widget.ArrayAdapter.(ArrayAdapter.java:128) at com.example.mohamed.movieapp.CustomArrayAdapter.(CustomArrayAdapter.java:25) at com.example.mohamed.movieapp.MainActivityFragment.onCreateView(MainActivityFragment.java:78) at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1036) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1226) at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1328) at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2284) at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:111) at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:314) at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:31) at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:79) at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:733) at android.view.LayoutInflater.inflate(LayoutInflater.java:482) at android.view.LayoutInflater.inflate(LayoutInflater.java:414) at android.view.LayoutInflater.inflate(LayoutInflater.java:365) at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:256) at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109) at com.example.mohamed.movieapp.MainActivity.onCreate(MainActivity.java:19) at android.app.Activity.performCreate(Activity.java:5990) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5254) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
thnks for advice and interaction
回答1:
So during onCreateView which gets called early in life cylce, you are trying to create array adapter out of empty uninitialized array. Please move setAdapter call to your post execute.
Note: any particular reason to update data in constructor? You are anyway calling it onStart.
来源：https://stackoverflow.com/questions/34443009/custom-arrayadapter-get-data-from-asynctask