android webview点击返回键返回上一级activity

1 @Override
2     public boolean onKeyDown(int keyCode, KeyEvent event) {
3         // TODO Auto-generated method stub
4         if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
5             return true;
6         }
7         return super.onKeyDown(keyCode, event);
8     }