
public class MainActivity extends AppCompatActivity {

    private ListView mDrawerList;
    private ArrayAdapter mAdapter;
    ...

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);


        mDrawerList = (ListView)findViewById(R.id.navList);

        mDrawerLayout = (DrawerLayout)findViewById(R.id.drawer_layout);

        addDrawerItems();

        mDrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id) {
                final Dialog aboutDialog = new Dialog(MainActivity.this);
                aboutDialog.setContentView(R.layout.about);
                aboutDialog.setCancelable(true);
                aboutDialog.show();
            }
        });
    }


    private void addDrawerItems() {
        String[] osArray = { "Profil bearbeiten", "Ein Problem melden", "Nutzungsbedingungen", "Kontakt", "Über uns" };
        mAdapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1, osArray);
        mDrawerList.setAdapter(mAdapter);
    }

}

...