/**
  * 獲取是否存在NavigationBar
  * @param context
  * @return
  */
 public boolean checkDeviceHasNavigationBar(Context context) {
  boolean hasNavigationBar = false;
  Resources rs = context.getResources();
  int id = rs.getIdentifier("config_showNavigationBar", "bool", "android");
  if (id > 0) {
   hasNavigationBar = rs.getBoolean(id);
  }
  try {
   Class systemPropertiesClass = Class.forName("android.os.SystemProperties");
   Method m = systemPropertiesClass.getMethod("get", String.class);
   String navBarOverride = (String) m.invoke(systemPropertiesClass, "qemu.hw.mainkeys");
   if ("1".equals(navBarOverride)) {
    hasNavigationBar = false;
   } else if ("0".equals(navBarOverride)) {
    hasNavigationBar = true;
   }
  } catch (Exception e) {
  }
  return hasNavigationBar;
 }
 /**
  * 獲取虛擬功能鍵高度
  * @param context
  * @return
  */
 public int getVirtualBarHeigh(Context context) {
  int vh = 0;
  WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
  Display display = windowManager.getDefaultDisplay();
  DisplayMetrics dm = new DisplayMetrics();
  try {
   @SuppressWarnings("rawtypes")
   Class c = Class.forName("android.view.Display");
   @SuppressWarnings("unchecked")
   Method method = c.getMethod("getRealMetrics", DisplayMetrics.class);
   method.invoke(display, dm);
   vh = dm.heightPixels - windowManager.getDefaultDisplay().getHeight();
  } catch (Exception e) {
   e.printStackTrace();
  }
  return vh;
 }