/** 
 * 隱藏虛擬按鍵，并且設(shè)置成全屏 
 */ 
 protected void hideBottomUIMenu(){ 
  if (Build.VERSION.SDK_INT > 11 && Build.VERSION.SDK_INT < 19) { // lower api 
   View v = this.getWindow().getDecorView(); 
   v.setSystemUiVisibility(View.GONE); 
  } else if (Build.VERSION.SDK_INT >= 19) { 
   //for new api versions. 
   View decorView = getWindow().getDecorView(); 
   int uiOptions = View.SYSTEM_UI_FLAG_LAYOUT_STABLE 
     | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION 
     | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN 
     | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION // hide nav bar 
      | View.SYSTEM_UI_FLAG_FULLSCREEN // hide status bar 
     | View.SYSTEM_UI_FLAG_IMMERSIVE; 
   decorView.setSystemUiVisibility(uiOptions); 
   getWindow().addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION); 
  } 
} 

/** 
 * 檢查是否存在虛擬按鍵欄 
 * @param context 
 * @return 
 */ 
  public static boolean hasNavBar(Context context) { 
   Resources res = context.getResources(); 
 //這種方式一定要注意寫(xiě)法要正確，內(nèi)部應(yīng)該是通過(guò)反射去調(diào)用的。
   int resourceId = res.getIdentifier("config_showNavigationBar", "bool", "android"); 
   if (resourceId != 0) { 
    boolean hasNav = res.getBoolean(resourceId); 
    // check override flag 
    String sNavBarOverride = getNavBarOverride(); 
    if ("1".equals(sNavBarOverride)) { 
     hasNav = false; 
    } else if ("0".equals(sNavBarOverride)) { 
     hasNav = true; 
    } 
    return hasNav; 
   } else { // fallback 
    return !ViewConfiguration.get(context).hasPermanentMenuKey(); 
   } 
  } 

  /** 
   * 判斷虛擬按鍵欄是否重寫(xiě) 
   * @return 
   */ 
  private static String getNavBarOverride() { 
   String sNavBarOverride = null; 
   if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) { 
    try { 
     Class c = Class.forName("android.os.SystemProperties"); 
     Method m = c.getDeclaredMethod("get", String.class); 
     m.setAccessible(true); 
     sNavBarOverride = (String) m.invoke(null, "qemu.hw.mainkeys"); 
    } catch (Throwable e) { 
   } 
  } 
  return sNavBarOverride; 
}