DrawerLayout可以配合一個ActionBarDrawerToggle，其構造方法如下

ActionBarDrawerToggle (Activity activity, 
                DrawerLayout drawerLayout, 
                int openDrawerContentDescRes, 
                int closeDrawerContentDescRes)

ActionBarDrawerToggle (Activity activity, 
                DrawerLayout drawerLayout, 
                Toolbar toolbar, 
                int openDrawerContentDescRes, 
                int closeDrawerContentDescRes)

參數說明

activity	Activity: The Activity hosting the drawer.
drawerLayout	DrawerLayout: The DrawerLayout to link to the given Activity's ActionBar
toolbar	Toolbar: The toolbar to use if you have an independent Toolbar.
openDrawerContentDescRes	int: A String resource to describe the "open drawer" action for accessibility
closeDrawerContentDescRes	int: A String resource to describe the "close drawer" action for accessibility

最后一直沒搞明白是什么，也沒見它發揮過作用，搜了很多文章，好像大家都飄過這兩個參數了，搜了好久終于明白了，其重點在于
accessibility!accessibility!accessibility!
官網對accessibility的解釋

Many Android users have different abilities that require them to interact with their Android devices in different ways. These include users who have visual, physical or age-related limitations that prevent them from fully seeing or using a touchscreen, and users with hearing loss who may not be able to perceive audible information and alerts.

Android provides accessibility features and services for helping these users navigate their devices more easily, including text-to-speech, haptic feedback, gesture navigation, trackball and directional-pad navigation. Android application developers can take advantage of these services to make their applications more accessible.

Android developers can also build their own accessibility services, which can provide enhanced usability features such as audio prompting, physical feedback, and alternative navigation modes. Accessibility services can provide these enhancements for all applications, a set of applications or just a single app.

簡單來說就是openDrawerContentDescRes與closeDrawerContentDescRes的內容不會顯示在屏幕上，但是可以通過accessibility services轉換成語音為那些視力不好的人服務。就是如此!