要创建一个fragment，必须创建一个fragment的子类。
除了基类fragment，还有：
DialogFragment
ListFragment
PreferenceFragment

与Activity的对应生命周期

运行

创建Fragment

方式一

<fragmentandroid:layout_width="wrap_content"android:layout_height="match_parent"android:layout_weight="1"android:id="@+id/title_fragment"android:name="com.example.fragmentapplication.TitleFragment"/>

方式二

//通过代码添加Fragmentprivate void addContentLayout() {FragmentManager fm = getSupportFragmentManager();//开启一个事务FragmentTransaction ft = fm.beginTransaction();contentFragment = new ContentFragment();//添加fragmentft.add(R.id.cf,contentFragment);
//        ft.remove()//删除
//        ft.replace()//替换ft.commit();}
//ContentFragment.java
public class ContentFragment extends Fragment {@Nullable@Overridepublic View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {View view = inflater.inflate(R.layout.content_layout,container,false);return view;}
}

管理Fragment

public class PopBackFragment extends Fragment {private String title;public PopBackFragment(){}@SuppressLint("ValidFragment")public PopBackFragment(String title){this.title = title;}//Fragment的传参方法
//    public static PopBackFragment getInstance(String title){
//        PopBackFragment p = new PopBackFragment();
//
//        Bundle b = new Bundle();
//        b.putString("title",title);
//        p.setArguments(b);
//        return p;
//    }@Nullable@Overridepublic View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {View view = inflater.inflate(R.layout.activity_pop_back_fragment,container,false);TextView tv = (TextView)view.findViewById(R.id.textView_text);tv.setText(title);return view;}
}

public void oneClick(View v){PopBackFragment p1 = new PopBackFragment("one");FragmentTransaction ft = getSupportFragmentManager().beginTransaction();ft.replace(R.id.content,p1);//把当前Fragment添加到Activity栈中ft.addToBackStack(null);ft.commit();}@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if(keyCode == KeyEvent.KEYCODE_BACK){if(getSupportFragmentManager().getBackStackEntryCount()==0){finish();}else {getSupportFragmentManager().popBackStack();}return true;}return super.onKeyDown(keyCode, event);}

与Activity交互

<!--fragment_menu-->
<?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:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MenuFragment"android:orientation="vertical"><Buttonandroid:id="@+id/button_news"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="News"/><Buttonandroid:id="@+id/button_music"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="Musics" /></LinearLayout><!--fragment_main-->
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MainFragment"><!-- TODO: Update blank fragment layout --><TextViewandroid:layout_width="match_parent"android:layout_height="match_parent"android:text="@string/hello_blank_fragment"android:id="@+id/value"android:gravity="center"/></FrameLayout>

//MenuFragmentimport android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;public class MenuFragment extends Fragment implements View.OnClickListener {private MyMenuListener myMenuListener;public MenuFragment() {}@Overridepublic void onAttach(Context context) {super.onAttach(context);myMenuListener = (MyMenuListener)context;}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {// Inflate the layout for this fragmentView view = inflater.inflate(R.layout.fragment_menu, container, false);view.findViewById(R.id.button_news).setOnClickListener(this);view.findViewById(R.id.button_music).setOnClickListener(this);return view;}@Overridepublic void onClick(View v) {switch (v.getId()){case R.id.button_news:myMenuListener.changeValue("news");break;case R.id.button_music:myMenuListener.changeValue("musics");break;}}//定义一个回调接口public static interface MyMenuListener{public void changeValue(String value);}}//MainFragment
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;public class MainFragment extends Fragment {private TextView tv_value;public MainFragment() {// Required empty public constructor}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {// Inflate the layout for this fragmentView view = inflater.inflate(R.layout.fragment_main, container, false);tv_value = (TextView)view.findViewById(R.id.value);return view;}public void changeTextViewValue(String value){tv_value.setText(value);}
}

//MainActivity
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;public class MainActivity3 extends AppCompatActivity implements MenuFragment.MyMenuListener{private MenuFragment menuFragment;private MainFragment mainFragment;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main3);menuFragment = (MenuFragment) getSupportFragmentManager().findFragmentById(R.id.menuFragment);mainFragment = (MainFragment) getSupportFragmentManager().findFragmentById(R.id.mainFragment);}@Overridepublic void changeValue(String value) {mainFragment.changeTextViewValue(value);}
}

PrefernceFragment

在res中新建一个名为xml的文件夹，在文件夹中新建一个preference.xml文件

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategoryandroid:title="是否打开声音"><CheckBoxPreferenceandroid:key="checkbox_preference"android:title="打开声音"android:summary="设置打开声音后可以自动开启音乐"/>
</PreferenceCategory><PreferenceCategoryandroid:title="城市"><EditTextPreferenceandroid:key="edittext_preference"android:title="昵称"android:summary="请输入昵称"android:dialogTitle="昵称" /><ListPreferenceandroid:key="list_preference"android:title="城市名称"android:summary="请选择一个城市"android:entries="@array/city"android:entryValues="@array/city"android:dialogTitle="城市名称" /></PreferenceCategory>
</PreferenceScreen>

然后新建一个fragment，实现addPreferencesFromResource方法

public class PerfsFragment extends PreferenceFragment {@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);addPreferencesFromResource(R.xml.preferences);}}

最后新建一个activity使用fragment

<fragmentandroid:layout_width="match_parent"android:layout_height="match_parent"android:id="@+id/prefs_fragment"android:name="com.example.fragmentapplication.PerfsFragment"/>