Ich bin neu in Android. Ich möchte bekommencontacts Daten mitloaderCallbacks Ich schreibe Code, aber hier ist ein Problem. Ich weiß nicht, warum das passiert. Kannst du das bitte überprüfen?

package com.example.arfan.myfirstapp;

import android.app.LoaderManager;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getSupportLoaderManager().initLoader(1, null, this); // ERROR IS HERE in 3rd Argument
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @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.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        Uri CONTENT_URI = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
        return new CursorLoader(this, CONTENT_URI, null, null, null, null);
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        Log.i("INFO","This is working");
        while(data.moveToNext()){
            Log.i("Cantacts : ",data.getString(data.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)));
        }
    }

    @Override
    public void onLoaderReset(Loader<Cursor> loader) {

    }
}

Es gibt irgendeine Art von Problem inthis Streit. Wenn ich diese Zeile entferne, tritt kein Fehler auf und ich habe auch kein Ergebnis gefunden. Ich habe diesen Code von einer Website gelesen, wie man Kontaktdaten in Android bekommGo to Site

Können Sie mir bitte mitteilen, wo das Problem liegt und wie ich es beheben kann. Vielen Dank

AKTUALISIEREN Konsole zeigt dies.

Error:(25, 34) error: method initLoader in class LoaderManager cannot be applied to given types;
required: int,Bundle,LoaderCallbacks<D>
found: int,<null>,MainActivity
reason: cannot infer type-variable(s) D
(argument mismatch; MainActivity cannot be converted to LoaderCallbacks<D>)
where D is a type-variable:
D extends Object declared in method <D>initLoader(int,Bundle,LoaderCallbacks<D>)