android - 方法 initLoader(int, Bundle, LoaderManager.LoaderCallbacks) 一直给我不适用的错误

Question

我卡在我的代码中，我正在使用抽屉布局，而在 fragment 布局上，我想在从数据库中获取人员列表后显示它。在 fragment 类中，当我使用游标适配器查询并将其设置为列表适配器时，错误显示:

类型 LoaderManager 中的方法 initLoader(int, Bundle, LoaderManager.LoaderCallbacks) 不适用于参数 (int, null, MainFragment)。

我哪里错了，请帮忙。如果您需要更多信息，请询问。下面是我的 fragment 类及其相应的布局代码。提前致谢。

fragment 类:

import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.Locale;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.bnkinfotech.corporatedirectory.Directory.Mobile;
import com.bnkinfotech.corporatedirectory.Directory.Telephone;

import android.app.ListFragment;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;

import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.LoaderManager.LoaderCallbacks;
//import android.support.v4.app.ListFragment;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.AsyncTaskLoader;
import android.support.v4.content.Loader;
import android.support.v4.content.CursorLoader;
import android.support.v4.widget.CursorAdapter;


public class MainFragment extends ListFragment implements LoaderCallbacks<Cursor> {

    String loginPref;
    String email;
    String updatedDate;
    String onlineemail = null;
    SharedPreferences prefAccount;
    protected Cursor cursor;
    protected ListAdapter adapter;
    protected SQLiteDatabase db;
    public static String ArgAccountNumber = "account_list_number";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


    }

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

        prefAccount = getActivity().getSharedPreferences("CoDiAccount", Context.MODE_PRIVATE);
        onlineemail = prefAccount.getString("email", "-1").toLowerCase();
        String directoryname = "CoDiApp" + onlineemail;
        SharedPreferences prefs = getActivity().getSharedPreferences(directoryname, Context.MODE_PRIVATE);
        loginPref = prefs.getString("login", "-1");
        email = prefs.getString("email", "-1").toLowerCase();
        updatedDate = prefs.getString("lastupdateddate", "-1");

        View rootView = inflater.inflate(R.layout.main_fragment, container, false);
        return rootView;
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
    }

    @Override
    public void onStart() {
        super.onStart();
        if (loginPref == "1")
        {
            showContacts();                
        }
        else if (loginPref == "0")
        {
            //Validate account
            Intent verifyAccount = new Intent(getActivity(), VerifyAccountActivity.class);
            getActivity().startActivity(verifyAccount);
        }
        else
        {
            //Email Login
            Intent checkEmail = new Intent(getActivity(), CheckEmailActivity.class);
            getActivity().startActivity(checkEmail);
        }
    }

    public int showContacts() {
        SharedPreferences prefAccount = getActivity().getSharedPreferences("CoDiAccount", Context.MODE_PRIVATE);
        String onlineemail = prefAccount.getString("email", "-1").toLowerCase(Locale.ENGLISH);
        String directoryname = "CoDiApp" + onlineemail;
        SharedPreferences prefs = getActivity().getSharedPreferences(directoryname, Context.MODE_PRIVATE);

        String loadxml = prefs.getString("loadxml", "-1");
        String groupBy = prefs.getString("groupby", "0");
        if (loadxml == "-1")
        {
            LoadXMLFile();
            Editor prefEditor = prefs.edit();
            prefEditor.putString("loadxml", "1");
            String timeStamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(Calendar.getInstance().getTime());
            prefEditor.putString("lastupdateddate", timeStamp.toString());
            prefEditor.commit();
        }

        String[] uiBindFrom = { SQLiteDB.FIRST_NAME, SQLiteDB.LAST_NAME };
        int[] uiBindTo = { R.id.firstName, R.id.lastName };

        getLoaderManager().initLoader(0, null, this);
        adapter = new SimpleCursorAdapter(
                getActivity().getApplicationContext(), R.layout.main_fragment,
                null, uiBindFrom, uiBindTo,
                CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);     
        setListAdapter(adapter); 
        return 1;
    }

    public void LoadXMLFile() {
        String response = "";
        RequestManager rm = new RequestManager();
        String x = "";
        ArrayList<Mobile> arrMob;
        ArrayList<Telephone> arrTel;

        try
        {
            if(isValidEmail(email))
            {
                String url = String.format("GetDirectory/{0}", email);
                response = rm.GetResponse(url);

                try {
                    // Create your Json Array
                    JSONArray lList=new JSONArray(response);
                    // Iterate the json array to get each Json object
                    for (int i = 0; i < lList.length(); i++) {

                        JSONObject lObject=lList.getJSONObject(i);

                        String fName=lObject.getString("FirstName");
                        String lName=lObject.getString("LastName");
                        String gName=lObject.getString("GroupName");

                        JSONArray jsonArr= lObject.getJSONArray("MobileNumbers");
                        Mobile[] mNumbers=new Mobile[jsonArr.length()];
                        arrMob = new ArrayList<Mobile>();
                        for(int j=0;j<jsonArr.length();j++)
                        {
                            mNumbers[j]= (Mobile) jsonArr.get(j);
                            arrMob.add(mNumbers[j]);
                        }

                        JSONArray jsonArrTel= lObject.getJSONArray("TelephoneNumbers");
                        Telephone [] tNumbers=new Telephone[jsonArrTel.length()];
                        arrTel = new ArrayList<Telephone>();
                        for(int k=0;k<jsonArrTel.length();k++)
                        {
                            tNumbers[k]=(Telephone) jsonArrTel.get(k);
                            arrTel.add(tNumbers[k]);
                        }
                        String hAddress=lObject.getString("HomeAddress");
                        String oAddress=lObject.getString("OfficeAddress");

                        //Code to Insert in Sqlite database .....
                        Directory dir = new Directory();
                        dir.setFirstName(fName);
                        dir.setLastName(lName);
                        dir.setGroupName(gName);
                        dir.setMobiles(arrMob);
                        dir.setTelephones(arrTel);
                        dir.setHomeAddress(hAddress);
                        dir.setOfficeAddress(oAddress);

                        DatabaseHandler dbHandler = new DatabaseHandler(getActivity().getApplicationContext());
                        SQLiteDatabase sqliteDatabase = dbHandler.getWritableDatabase();
                        ContentValues contentValues = new ContentValues();

                        contentValues.put(DatabaseHandler.ID, dir.getId());
                        contentValues.put(DatabaseHandler.FIRST_NAME, dir.getFirstName());
                        contentValues.put(DatabaseHandler.LAST_NAME, dir.getLastName());
                        contentValues.put(DatabaseHandler.GROUP_NAME, dir.getGroupName());

                        contentValues.put(DatabaseHandler.MOBILES, dir.getMobiles().toString());
                        contentValues.put(DatabaseHandler.TELEPHONES, dir.getTelephones().toString());
                        contentValues.put(DatabaseHandler.HOME_ADDRESS, dir.getHomeAddress());
                        contentValues.put(DatabaseHandler.OFFICE_ADDRESS, dir.getOfficeAddress());

                        sqliteDatabase.insert(DatabaseHandler.TABLE_NAME_MEMBER, null, contentValues);
                        sqliteDatabase.close();
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
            else
            {
                String msg = "Sorry, invalid email";
                Toast.makeText(getActivity().getApplicationContext(), msg, Toast.LENGTH_LONG).show();
            }
        }
        catch (Exception ex)
        {
            response = ex.getMessage().toString();
        }
    }
    public final static boolean isValidEmail(CharSequence email) {
        if (email == null) {
            return false;
        } else {
            return android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches();
        }
    }

    @Override
    public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) {
        String[] projection = { SQLiteDB.ID, SQLiteDB.FIRST_NAME, SQLiteDB.LAST_NAME };

        CursorLoader cursorLoader = new CursorLoader(getActivity(),
                DatabaseAccessUtility.CONTENT_URI, projection, null, null, null);
        return cursorLoader;
    }

    @Override
    public void onLoadFinished(Loader<Cursor> arg0, Cursor arg1) {
        ((SimpleCursorAdapter) adapter).swapCursor(arg1);
    }

    @Override
    public void onLoaderReset(Loader<Cursor> arg0) {
        ((SimpleCursorAdapter) adapter).swapCursor(null);
    } 

}

MainFragment 布局:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:minWidth="25dp"
    android:minHeight="25dp"
    android:id="@+id/FlyOutContent">
    <LinearLayout
        android:id="@+id/linlaHeaderProgress"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:gravity="center"
        android:orientation="vertical"
        android:visibility="gone">
        <ProgressBar
            android:id="@+id/pbHeaderProgress"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </LinearLayout>

   <RelativeLayout
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="8dp" >

    <TextView
        android:id="@+id/firstName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="First" />

    <TextView
        android:id="@+id/lastName"
        android:layout_marginLeft="6dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/firstName"
        android:text="Last" />

    </RelativeLayout>
    <LinearLayout
        android:orientation="vertical"
        android:minWidth="25dp"
        android:minHeight="25dp"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@android:id/empty">
        <TextView
            android:text="@string/NoFavoritesText"
            android:textAppearance="?android:attr/textAppearanceMedium"
            android:layout_width="fill_parent"
            android:layout_height="match_parent"
            android:id="@+id/textView1"
            android:gravity="center"
            android:layout_marginLeft="12dip"
            android:layout_marginRight="12dip"
            android:textColor="#ff5a5a5a"
            android:layout_marginTop="80dip" />
    </LinearLayout>
</LinearLayout>

Answer 1

由于您使用的是支持库，因此请改用:

getActivity().getSupportLoaderManager().initLoader(0, null, this);