使用了Navigation,则必然存在一个NavHostFragment,其它的Fragment都是它的子Fragment,所以,想获取其它fragment,就要从它的子fragment中获取,参考示例:
//先获取NavHostFragment
Fragment mMainNavFragment = getSupportFragmentManager().findFragmentById(nav_host_fragment_content_main);
//再获取当前的Fragment
Fragment fra = mMainNavFragment.getChildFragmentManager().getPrimaryNavigationFragment();
//判断当前的fragment是否是自己想要的Fragment
if (fra instanceof ScanFragment) { //如果是,就转成目标Fragment,就可以调用它的公开方法及公开属性ScanFragment fra=(ScanFragment)frag;//调用该frangment的公开方法fra.Reset(); }
参考:https://www.zhihu.com/question/360688235/answer/974850558