好。我有一个扩展Fragment的Class是该类的内容 的 Category.java
public class Category extends Fragment {
private TextView cat_txt1;
private TextView cat_txt2;
private TextView cat_txt3;
private TextView cat_txt4;
private TextView cat_txt5;
private TextView cat_txt6;
private TextView cat_txt7;
private TextView cat_txt8;
private TextView cat_txt9;
private TextView cat_txt10;
private AppController app_controller;
public static FAQ newInstance(String title) {
FAQ fragmentFirst = new FAQ();
/*Bundle args = new Bundle();
args.putInt("someInt", page);
args.putString("someTitle", title);
fragmentFirst.setArguments(args);*/
return fragmentFirst;
}
//TextView TvFAQ;
// Store instance variables based on arguments passed
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
app_controller=new AppController();
Toast.makeText(getActivity(), "inflated",
Toast.LENGTH_LONG).show();
View view = inflater.inflate(R.layout.fragment_category, container, false);
cat_txt1=(TextView) view.findViewById(R.id.txt_cat1);
cat_txt2=(TextView) view.findViewById(R.id.txt_cat2);
cat_txt3=(TextView) view.findViewById(R.id.txt_cat3);
cat_txt4=(TextView) view.findViewById(R.id.txt_cat4);
cat_txt5=(TextView) view.findViewById(R.id.txt_cat5);
cat_txt6=(TextView) view.findViewById(R.id.txt_cat6);
cat_txt7=(TextView) view.findViewById(R.id.txt_cat7);
cat_txt8=(TextView) view.findViewById(R.id.txt_cat8);
cat_txt9=(TextView) view.findViewById(R.id.txt_cat9);
cat_txt10=(TextView) view.findViewById(R.id.txt_cat10);
load_categories(MetaInfo.getMetadata(getActivity(),"yapplication_id"));
return view;
}
private void load_categories(final String application_id){
// Tag used to cancel the request
String tag_json_obj = "json_obj_req";
Toast.makeText(getActivity(), application_id,
Toast.LENGTH_LONG).show();
String url = getResources().getString(R.string.ybase_path)+"getjson.php";
///ProgressDialog pDialog = new ProgressDialog(this);
//pDialog.setMessage("Loading...");
//pDialog.show();
JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
url, null,
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
Log.d("rewangojson", response.toString());
//pDialog.hide();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("json err", "Error: " + error.getMessage());
// pDialog.hide();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put("application_id", application_id);
return params;
}
};
// Adding request to request queue
app_controller.addToRequestQueue(jsonObjReq, tag_json_obj);
}
}
我正在使用以下代码
在我的Dashboard Activity中动态添加上述类FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Category category = new Category();
fragmentTransaction.add(R.id.dashboard_fragment_conatiner, category, "Category");
fragmentTransaction.commit();
我在Category.java上调用函数addToRequestQueue（）。该函数存在于类名AppController中。以下是AppController类中的代码。我在AppController类中得到错误。
public class AppController extends Application {
public static final String TAG = AppController.class
.getSimpleName();
private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;
private static AppController mInstance;
@Override
public void onCreate() {
super.onCreate();
mInstance = this;
}
public static synchronized AppController getInstance() {
return mInstance;
}
public RequestQueue getRequestQueue() {
if (mRequestQueue == null) {
mRequestQueue = Volley.newRequestQueue(getApplicationContext());
}
return mRequestQueue;
}
public ImageLoader getImageLoader() {
getRequestQueue();
if (mImageLoader == null) {
mImageLoader = new ImageLoader(this.mRequestQueue,
new LruBitmapCache());
}
return this.mImageLoader;
}
public <T> void addToRequestQueue(Request<T> req, String tag) {
// set the default tag if tag is empty
req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
getRequestQueue().add(req);
}
public <T> void addToRequestQueue(Request<T> req) {
req.setTag(TAG);
getRequestQueue().add(req);
}
public void cancelPendingRequests(Object tag) {
if (mRequestQueue != null) {
mRequestQueue.cancelAll(tag);
}
}
}
以下是我的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="demo.if">
<!-- To auto-complete the email text field in the login form with the user's emails -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.READ_PROFILE" />
<uses-permission android:name="android.permission.READ_CONTACTS" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<!--
The ACCESS_COARSE/FINE_LOCATION permissions are not required to use
Google Maps Android API v2, but you must specify either coarse or fine
location permissions for the 'MyLocation' functionality.
-->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:name=".helpers.classes.ConnectivityListenerSet"
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true">
<activity
android:name=".Dashboard"
android:label="@string/app_name"
android:theme="@style/AppTheme.NoActionBar" />
<activity
android:name=".Entry"
android:label="@string/title_activity_entry"
android:launchMode="singleTask"
android:theme="@style/AppTheme">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.facebook.FacebookActivity"
android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
android:label="@string/app_name" />
<receiver
android:name=".helpers.classes.ConnectivityReceiver"
android:enabled="true">
<intent-filter>
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
</intent-filter>
</receiver>
<activity
android:name=".TabbedContent"
android:label="@string/about"
android:theme="@style/NoAB"
></activity>
</application>
</manifest>