ListView来自手机通讯录

Question

下面的应用程序应该创建已保存联系人的简单列表视图。

它是compliles但是在android studio的模拟器上试用时应用程序一直停止。

任何帮助将不胜感激。提前致谢

package com.example.list_app2;

import android.database.Cursor;
import android.provider.ContactsContract;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.SimpleCursorAdapter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;

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


    SimpleCursorAdapter mAdapter;
    ListView myList;
    static final String[] PROJECTION = new String[] {ContactsContract.Data._ID, ContactsContract.Data.DISPLAY_NAME};
    static final String SELECTION = "((" + ContactsContract.Data.DISPLAY_NAME + " NOTNULL) AND (" + ContactsContract.Data.DISPLAY_NAME + " != '' ))";



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        myList = (ListView)findViewById(R.id.ContactList);

        String[] fromColumns = {ContactsContract.Data.DISPLAY_NAME};
        int[] toViews = {android.R.id.text1};
        mAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, null, fromColumns, toViews, 0);
        myList.setAdapter(mAdapter);

        getLoaderManager().initLoader(0, null, (android.app.LoaderManager.LoaderCallbacks<Cursor>)this);

    }
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {

        mAdapter.swapCursor(data);
    }

    public void onLoaderReset(Loader<Cursor> loader) {

        mAdapter.swapCursor(null);
    }

    public Loader<Cursor> onCreateLoader(int id, Bundle args) {

        return new CursorLoader(this, ContactsContract.Data.CONTENT_URI,
                PROJECTION, SELECTION, null, null);
    }


}