如何使用正则表达式删除括号/括号之间的所有非数字字符？(How to remove all non numeric characters between brackets/parentheses with a regex?)

 问题是您没有真正使用您的片段，因为您没有在activity添加它。 一个简单的解决方法是为您的活动定义一个独立的布局： 
 
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:id="@+id/fragment_container"
             xmlns:android="http://schemas.android.com/apk/res/android"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:orientation="vertical">

</FrameLayout>
 
 现在，在您的活动中将fragment添加到此容器中： 
 
setContentView(R.layout.home_activity_layout);

MainActivityFragment myFragment = new MainActivityFragment();
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().add(R.id.fragment_container, myFragment, MainActivityFragment.class.getName()).commit();
 
 应该这样做。 

The issue is that you aren't really using your fragment because you aren't adding it in your activity. A simple fix would be to define an independent layout for your activity as:
 
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:id="@+id/fragment_container"
             xmlns:android="http://schemas.android.com/apk/res/android"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:orientation="vertical">

</FrameLayout>
 
Now, within your activity add the fragment to this container:
 
setContentView(R.layout.home_activity_layout);

MainActivityFragment myFragment = new MainActivityFragment();
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().add(R.id.fragment_container, myFragment, MainActivityFragment.class.getName()).commit();
 
That should do it.