参考《Professional Android 4 Development》
Fragment简介
创建Fragment
package test.fragments;import android.app.Fragment;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;public class MySkeletonFragment extends Fragment {@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Create, or inflate the Fragment’s UI, and return it. // If this Fragment has no UI then return null. return inflater.inflate(R.layout.my_fragment, container, false); }}Fragment生命周期
Fragment
Fragment特有的生命周期事件获取FragmentManager
FragmentManagerfragmentManager=getFragmentManager();
在Activity中添加Fragment的最简单方法是使用layout配置文件，，例如：
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="match_parent"> <fragment android:name="com.paad.weatherstation.MyListFragment" android:id="@+id/my_list_fragment" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" /> <fragment android:name="com.paad.weatherstation.DetailsFragment" android:id="@+id/details_fragment" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="3" /></LinearLayout>
调用inflate方法生成Fragment的界面后，Fragment实际上是一个类似ViewGroup的角色，在Activity中管理自己的UI。
上面那种将Fragment添加到Activity的方法缺乏灵活性，不能实现动态地添加和删除，更好的方式是使用FragmentTranaction和类似下面这样的配置文件：
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="match_parent"> <FrameLayout android:id="@+id/ui_container" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" /> <FrameLayout android:id="@+id/details_container" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="3" /></LinearLayout>使用FragmentTransaction
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();// Add, remove, and/or replace Fragments.// Specify animations.// Add to back stack if required.fragmentTransaction.commit();添加，删除和替换Fragment
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();fragmentTransaction.add(R.id.ui_container, new MyListFragment());fragmentTransaction.commit();
删除Fragment需要FragmentTransaction的remove()方法，参数为Fragment对象，Fragment对象可以通过FragmentManager的findFragmentById()方法获得。
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();Fragment fragment = fragmentManager.findFragmentById(R.id.details_fragment);fragmentTransaction.remove(fragment);fragmentTransaction.commit();
替换Fragment使用的是FragmentTransaction的replace()方法，参数分别为所要替代Fragment所在容器的ID和新的Fragment：
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();fragmentTransaction.replace(R.id.details_fragment, new DetailFragment(selected_index));fragmentTransaction.commit();获取指定的Fragment
MyFragment myFragment = (MyFragment)fragmentManager.findFragmentById(R.id.MyFragment);
也可以通过创建Fragment时添加的tag获取特定的Fragment：
MyFragment myFragment = (MyFragment)fragmentManager.findFragmentByTag(MY_FRAGMENT_TAG);删除Fragment容器
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="match_parent"> <FrameLayout android:id="@+id/ui_container" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" /> <FrameLayout android:id="@+id/details_container" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="3" android:visibility="gone" /></LinearLayout>Fragment和BackStack人生最大的错误是不断担心会犯错
