Android 片段中的ListView空点异常

我试图从mysql数据库中填充listfragment中的列表。 但我得到了空指针异常。我在活动中也做了同样的事情，效果很好。请建议

这是我的列表片段

public class AllPatient extends ListFragment {


    // Creating JSON Parser object
    JSONParser jParser = new JSONParser();

    ArrayList < HashMap < String, String >> productsList = new ArrayList < HashMap < String, String >> ();

    // url to get all products list
    private static String url_all_patients = "http://192.168.44.208/get_all_patients.php";

    // JSON Node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_PRODUCTS = "products";
    private static final String TAG_PATIENT_ID = "patient_id";
    private static final String TAG_PATIENT_NAME = "patient_name";

    JSONArray products = null;

    Context ctx;
    String pid;
    EditText inputSearch = null;
    ListAdapter adapter;


    @
    Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.patient_list, container, false);

        new LoadAllPatients().execute();
        //ListView lv =view.getListView();

        ListView v;
        /**/
        Getting Null Point Exception here * *
            v = (ListView) getView().findViewById(R.id.list);

        v.setOnItemClickListener(new OnItemClickListener() {

            @
            Override
            public void onItemClick(AdapterView <? > parent, View view,
                int position, long id) {
                // getting values from selected ListItem
                String pid = ((TextView) view.findViewById(R.id.pid)).getText()
                    .toString();
                System.out.println("doctor page" + pid);
                // Starting new intent
                Bundle bundle = new Bundle();
                bundle.putString("TAG_PATIENT_ID", pid);
                System.out.println("all patient" + pid);
                Intent i = new Intent(getActivity(), DocPresc.class);
                i.putExtras(bundle);
                startActivity(i);

                // starting new activity and expecting some response back
                //  startActivityForResult(in, 100);
            }
        });


        return view;
    }


    class LoadAllPatients extends AsyncTask < String, String, String > {


        protected String doInBackground(String...args) {
            // Building Parameters
            List < NameValuePair > params = new ArrayList < NameValuePair > ();
            // getting JSON string from URL
            JSONObject json = jParser.makeHttpRequest(url_all_patients, "GET", params);

            // Check your log cat for JSON reponse
            Log.d("All Patients: ", json.toString());

            try {
                // Checking for SUCCESS TAG
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // products found
                    // Getting Array of Products
                    products = json.getJSONArray(TAG_PRODUCTS);

                    // looping through All Products
                    for (int i = 0; i < products.length(); i++) {
                        JSONObject c = products.getJSONObject(i);

                        // Storing each json item in variable
                        String id = c.getString(TAG_PATIENT_ID).toUpperCase();
                        String name = c.getString(TAG_PATIENT_NAME).toUpperCase();

                        // creating new HashMap
                        HashMap < String, String > map = new HashMap < String, String > ();

                        // adding each child node to HashMap key => value
                        map.put(TAG_PATIENT_ID, id);
                        map.put(TAG_PATIENT_NAME, name);

                        // adding HashList to ArrayList
                        productsList.add(map);

                    }
                } else {

                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }


        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            // dismiss the dialog after getting all products
            //  pDialog.dismiss();
            // updating UI from Background Thread

            getActivity().runOnUiThread(new Runnable() {
                public void run() {

                    ListAdapter adapter = new SimpleAdapter(
                        getActivity(), productsList,
                        R.layout.list_item1, new String[] {
                            TAG_PATIENT_ID,
                            TAG_PATIENT_NAME
                        },
                        new int[] {
                            R.id.pid, R.id.name
                        });
                    // updating listview
                    setListAdapter(adapter);


                }

            });

        }

    }
}

替换

 v = (ListView)getView().findViewById(R.id.list);

与

假设您的列表视图包含在R.layout.patient_列表中

 v = (ListView) getView().findViewById(R.id.list);

借

---

你有两个选择

使用（如果没有布局文件）

或

---

在清单更改中，

android:id=“@+id/list”

更改为

android:id=“@android:id/list”

发布堆栈跟踪。是的，列表视图位于患者列表布局中。现在我得到的错误是：06-11 17:01:51.811:E/AndroidRuntime（24774）：java.lang.RuntimeException：您的内容必须有一个id属性为“android.R.id.list”的ListView，检查您的布局患者列表是否包含id为“list”的ListView。您正在使用ListActivity吗？或者（我想）是什么？如果是这样，他们希望您将该ID用于listview。你应该能够在谷歌上搜索它（“android.R.id.list”），看看为什么。我已经用过了…它很有效。请参阅文档：。。。您的视图层次结构必须包含一个id为“@android:id/list”的ListView对象（如果是代码，则为list）Thnx很多…但现在我还有一个问题。当我点击我的列表项目时，只有第一个项目的id会进入下一个活动。当我在这个列表片段中获取患者姓名和id并将患者id传递给另一个活动时，即使我点击了另一个项目，也只有第一个列表项目的id在传递…希望你明白我的意思。。。

06-11 16:55:33.264: E/AndroidRuntime(23430): FATAL EXCEPTION: main
06-11 16:55:33.264: E/AndroidRuntime(23430): java.lang.NullPointerException
06-11 16:55:33.264: E/AndroidRuntime(23430):    at com.example.actionbar.AllPatient.onCreateView(AllPatient.java:79)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1460)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:911)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:461)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.view.ViewPager.populate(ViewPager.java:1011)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.view.ViewPager.populate(ViewPager.java:880)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1374)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.View.measure(View.java:15479)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:617)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:399)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.View.measure(View.java:15479)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4828)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.View.measure(View.java:15479)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.View.measure(View.java:15479)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4828)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2359)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.View.measure(View.java:15479)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1968)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1214)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1387)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4464)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.Choreographer.doCallbacks(Choreographer.java:555)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.Choreographer.doFrame(Choreographer.java:525)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.os.Handler.handleCallback(Handler.java:615)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.os.Handler.dispatchMessage(Handler.java:92)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.os.Looper.loop(Looper.java:137)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at android.app.ActivityThread.main(ActivityThread.java:4895)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at java.lang.reflect.Method.invokeNative(Native Method)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at java.lang.reflect.Method.invoke(Method.java:511)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
06-11 16:55:33.264: E/AndroidRuntime(23430):    at dalvik.system.NativeStart.main(Native Method)

 v = (ListView)getView().findViewById(R.id.list);

 v = (ListView) view.findViewById(R.id.list);

 v = (ListView) getView().findViewById(R.id.list);

 v = (ListView) view.findViewById(R.id.list);

v = getListView(); 

v = (ListView) view.findViewById(android.R.id.list);