問號而不是RTL字段

我用這個Material Design Toolbar爲我的項目。問號而不是RTL字段

但我有2個問題：

當我使用一個RTL字符串的標籤名稱，它不顯示字符串正確

private String titles[] = new String[]{"تست", "Sample Tab 2", "Sample Tab 3", "Sample Tab 4" 
    , "Sample Tab 5", "Sample Tab 6", "Sample Tab 7", "Sample Tab 8"};

裏面的OnCreate：

mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); 
mDrawerList = (ListView) findViewById(R.id.navdrawer); 
toolbar = (Toolbar) findViewById(R.id.toolbar); 
if (toolbar != null) { 
    setSupportActionBar(toolbar); 
    toolbar.setNavigationIcon(R.drawable.ic_ab_drawer); 
} 
pager = (ViewPager) findViewById(R.id.viewpager); 
slidingTabLayout = (SlidingTabLayout) findViewById(R.id.sliding_tabs); 
pager.setAdapter(new ViewPagerAdapter(getSupportFragmentManager(), titles));

This顯示：

enter image description here