Android之Fragment案例解析

创建工程fragmentdamel


第一步创建Data.java

package com.example.fragmentdamel;public final class Data {//标题public static final String[] TITLES={"线性布局","表格布局","帧布局","相对布局",};//详细内容public static final String[] DETAIL = {"线性布局","表格布局","帧布局","相对布局"};}

第二步：
创建DetailFragment

package com.example.fragmentdamel;import android.app.Fragment;import android.os.Bundle;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.ScrollView;import android.widget.TextView;public class DetailFragment extends Fragment {public static DetailFragment newInstance(int index){DetailFragment f = new DetailFragment();Bundle bundle = new Bundle();bundle.putInt("index", index);//将索引值添加到Bundle对象中f.setArguments(bundle);//将bundle对象作为Fragment的参数保存return f;}public int getShownIndex(){return getArguments().getInt("index",0);//获取要显示的列表项的索引}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {// TODO Auto-generated method stub//return super.onCreateView(inflater, container, savedInstanceState);if(container == null){return null;}ScrollView scroller = new ScrollView(getActivity());//创建一个滚动视图TextView text = new TextView(getActivity());//创建一个文本框对象text.setPadding(10, 10, 10, 10);//设置内边框scroller.addView(text);//将文本框添加到滚动视图中text.setText(Data.DETAIL[getShownIndex()]);//设置文本框要显示的内容return scroller;}}

第三步
创建ListFragment

package com.example.fragmentdamel;import android.app.FragmentTransaction;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.ArrayAdapter;import android.widget.ListView;public class ListFragment extends android.app.ListFragment{boolean dualPane;int curCheckPosition = 0;@Overridepublic void onActivityCreated(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onActivityCreated(savedInstanceState);//为列表设置适配器setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_checked,Data.TITLES));//获取布局文件添加的FragmentLayout帧布局管理器View detailFrame = getActivity().findViewById(R.id.detail);//判断是否在一屏上同时显示列表和详细内容dualPane = detailFrame != null && detailFrame.getVisibility() ==View.VISIBLE;//更新当前选择的索引位置if(savedInstanceState != null){curCheckPosition = savedInstanceState.getInt("curChoice",0);}//如果在一屏上同时显示列表和详细内容if(dualPane){//设置列表为单选模式getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);showDetails(curCheckPosition);//显示详细内容}}//重写方法@Overridepublic void onSaveInstanceState(Bundle outState) {// TODO Auto-generated method stubsuper.onSaveInstanceState(outState);outState.putInt("curChoice", curCheckPosition);}@Overridepublic void onListItemClick(ListView l, View v, int position, long id) {// TODO Auto-generated method stubshowDetails(position);//显示详细内容}void showDetails(int index){curCheckPosition = index;//更新保存当前索引位置的变量的值为当前选中值if(dualPane){//当在一屏上同时显示列表和详细内容时getListView().setItemChecked(index, true);//设置选中列表为选中状态DetailFragment details = (DetailFragment) getFragmentManager().findFragmentById(R.id.detail);//获取用于显示详细内容的Fragmentif(details == null || details.getShownIndex()!=index){//创建一个新的DetailFragment实例用于显示当前选择项对应的详细内容details = DetailFragment.newInstance(index);//要在activity中管理fragment 需要使用FragmentManagerFragmentTransaction ft = getFragmentManager().beginTransaction();//获得一个FragmentTransaction的实例ft.replace(R.id.detail, details);//替换原来显示的详细内容ft.addToBackStack(null);ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);//设置转换效果ft.commit();//提交事务}else {//在一屏上只能显示列表或一个详细内容时Intent intent = new Intent(getActivity(), MainActivity.DetailActivity.class);intent.putExtra("index", index);startActivity(intent);}}}}

第五步创建MainActivity

package com.example.fragmentdamel;import android.os.Bundle;import android.app.Activity;import android.content.res.Configuration;import android.view.Menu;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);}//创建一个继承Activity的内部类，用于在手机界面中通过Activity显示详细内容public static  class DetailActivity extends Activity{@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);//判断是否为横屏如果为横屏，结束当前的Activity，准备使用Fragment显示详细内容if(getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE){finish();return ;}if(savedInstanceState == null){//在初始化时插入一个显示详细内容的FragmentDetailFragment details = new DetailFragment();details.setArguments(getIntent().getExtras());//设置要传递的参数getFragmentManager().beginTransaction().add(android.R.id.content, details).commit();//添加一个显示详细内容的Fragment}}}}

创建main_layout.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="horizontal" >    <fragment        android:id="@+id/titles"        android:layout_width="0px"        android:layout_height="match_parent"        android:layout_weight="1"        class="com.example.fragmentdamel.ListFragment" />    <FrameLayout        android:id="@+id/detail"        android:layout_width="0dp"        android:layout_height="match_parent"        android:layout_weight="2"        android:background="?android:attr/detailsElementBackground" >    </FrameLayout></LinearLayout>