mDrawerToggle = new ActionBarDrawerToggle(
		this,
		mDrawer,
		R.drawable.ic_navigation_drawer, // Drawer 的 Icon，那三条线
		R.string.file,
		R.string.app_name
) {
	@Override
	public void onDrawerOpened(View drawerView) {
		getSupportActionBar().setTitle(R.string.file);
	}
 
	@Override
	public void onDrawerClosed(View drawerView) {
		getSupportActionBar().setTitle(R.string.app_name);
	}
};
mDrawer.setDrawerListener(mDrawerToggle);
//getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 
// 以下是显示那三条线的关键
mDrawer.post(new Runnable() {
	@Override
	public void run() {
		mDrawerToggle.syncState();
	}
});