public class PlaceholderFragment extends Fragment { // android.support.v4.app.Fragment;    public PlaceholderFragment() {}    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        View rootView = inflater.inflate(R.layout.fragement_main, container, false);        rootView.findViewById(R.id.btnShowAnotherFrament).setOnClickListener(new View.OnClickListener(){            public void onClick(View v) {
　　　　　　　　　// 启动另外一个 Fragment                getFragmentManager().beginTransaction()                        .addToBackStack(null)  // 添加后退栈  不然的后退的话没有效果                        .replace(R.id.container, new AnotherFragment())   // 在这个容器里面替换 新的Fragment                        .commit();            }        });        rootView.findViewById(R.id.btnStartSliderActivity).setOnClickListener(new View.OnClickListener(){            @Override            public void onClick(View v) {                getFragmentManager().popBackStack();            }        });        return rootView;    }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context=".MainActivity$PlaceholderFragment">    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="呈现另一个Fragement"        android:id="@+id/btnShowAnotherFrament" /></LinearLayout>

 protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        if (savedInstanceState == null) {            getSupportFragmentManager().beginTransaction().add(R.id.container, new PlaceholderFragment())                    .commit();        }        System.out.println("onCreate");    }