15 ActionBar.Tab 以及保存fragment对象 代码案例

• API 21弃用

• values 中 string文件源码:

  <?xml version="1.0" encoding="utf-8"?>
  <resources>
  
      <string name="app_name">Day15_Actionbar_demo4</string>
      <string name="action_settings">Settings</string>
      <string name="hello_world">Hello world!</string>
      <!--
          nums 对应网址
        -->
      <string-array name="paths">
          <item>http://c.m.163.com/nc/article/headline/T1348647853363/0-20.html</item>
          <item>http://c.m.163.com/nc/article/list/T1348648517839/0-20.html</item>
          <item>http://c.m.163.com/nc/article/list/T1348649079062/0-20.html</item>
          <item>http://c.m.163.com/nc/article/list/T1348648756099/0-20.html</item>
      </string-array>
      <!--由于地址返回json的根目录中只有这个名字 所以写死每个地址的根目录名 就可以只用一个解析了  -->
      <string-array name="nums">
          <item>T1348647853363</item>
          <item>T1348648517839</item>
          <item>T1348649079062</item>
          <item>T1348648756099</item>
      </string-array>
  
  </resources>

• activity_main.xml源码:

  
  
  <!-- 直接作为fragment的容器 -->
  <RelativeLayout 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"
      android:id="@+id/rl_fragment_id"
      tools:context=".MainActivity" >
  
  </RelativeLayout>
  

• fragment填充对象源码:

  <?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="vertical" >
  
      <ListView
          android:id="@+id/lv"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          />
  
  </LinearLayout>
  

• MainActivity.java:

  package com.qf.day15_actionbar_demo4;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import com.qf.day15_actionbar_demo4.fragment.MyFragment;
  
  import android.os.Bundle;
  import android.app.ActionBar;
  import android.app.ActionBar.Tab;
  import android.app.ActionBar.TabListener;
  import android.app.Activity;
  import android.app.Fragment;
  import android.app.FragmentTransaction;
  import android.util.Log;
  import android.view.Menu;
  import android.widget.Toast;
  
  public class MainActivity extends Activity implements TabListener{
  
      private Map<Integer, Fragment> fragmentMap;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
          //将集合实例化
          fragmentMap = new HashMap<Integer, Fragment>();
  
          //获取ActionBar
          ActionBar actionBar = getActionBar();
          //设置导航模式
          actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
  
          ActionBar.Tab tab = actionBar.newTab();
          tab.setIcon(android.R.drawable.ic_menu_add);
          tab.setText("头条");
          tab.setTabListener(this);
          actionBar.addTab(tab, true);
  
          tab = actionBar.newTab();
          tab.setIcon(android.R.drawable.ic_menu_call);
          tab.setText("娱乐");
          tab.setTabListener(this);
          actionBar.addTab(tab);
  
          tab = actionBar.newTab();
          tab.setIcon(android.R.drawable.ic_menu_camera);
          tab.setText("财经");
          tab.setTabListener(this);
          actionBar.addTab(tab);
  
          tab = actionBar.newTab();
          tab.setIcon(android.R.drawable.ic_menu_crop);
          tab.setText("体育");
          tab.setTabListener(this);
          actionBar.addTab(tab);
      }
  
      /**
       * 选择Tab 事件监听
       */
      @Override
      public void onTabSelected(Tab tab, FragmentTransaction ft) {
          // TODO Auto-generated method stub
          //你点击的是那个Tab 位置获取出来
  //      int pos = tab.getPosition();
  //
  //      MyFragment myFragment = new MyFragment();
  //
  //      Bundle bundle = new Bundle();
  //      bundle.putInt("pos", pos);
  //      myFragment.setArguments(bundle);
  //
  //
  //      ft.replace(R.id.rl_fragment_id, myFragment);
  //      //.commit();  不需要加提交  不需要 添加回退
  
          Log.e("AAA", tab.getPosition()+"");
  
          Fragment fragment = fragmentMap.get(tab.getPosition());
  
          if(fragment==null){
              fragment = new MyFragment();
              Bundle bundle = new Bundle();
              bundle.putInt("pos", tab.getPosition());
              fragment.setArguments(bundle);
              fragmentMap.put(tab.getPosition(), fragment);
              ft.add(R.id.rl_fragment_id, fragment);
  
          }else{
              ft.show(fragment);
          }
      }
  
      /**
       * 重选Tab  双击
       */
      @Override
      public void onTabReselected(Tab tab, FragmentTransaction ft) {
          // TODO Auto-generated method stub
  
      }
  
      /**
       * 用户选择另一个tab标签的时候触发
       */
      @Override
      public void onTabUnselected(Tab tab, FragmentTransaction ft) {
          // TODO Auto-generated method stub
          //没有被选择的Tab
          Fragment fragment = fragmentMap.get(tab.getPosition());
          Toast.makeText(this, tab.getPosition()+"", 0).show();
          if(fragment!=null){
              ft.hide(fragment);
          }
      }
  
  }

• MyTask.java 一个异步任务 用于加载网络数据:

  package com.qf.day15_actionbar_demo4.asynctask;
  
  import java.util.List;
  
  import com.qf.day15_actionbar_demo4.interface0.CallBackData;
  import com.qf.day15_actionbar_demo4.utils.HttpUtils;
  import com.qf.day15_actionbar_demo4.utils.ParseJson;
  
  import android.os.AsyncTask;
  
  public class MyTask extends AsyncTask<String, Void, List<String>>{
  
      private String num;
      private CallBackData callBackData;
  
      public MyTask(String num,CallBackData callBackData){
          this.num = num;
          this.callBackData = callBackData;
      }
  
      @Override
      protected List<String> doInBackground(String... params) {
          // TODO Auto-generated method stub
          String jsonStr = HttpUtils.getStr(params[0]);
          //解析数据
          return ParseJson.getData(num, jsonStr);
      }
  
      @Override
      protected void onPostExecute(List<String> result) {
          // TODO Auto-generated method stub
          super.onPostExecute(result);
  
          if(result!=null&&result.size()>0){
              callBackData.sendData(result);
          }
  
      }
  
  }
  

• Fragment.java :

  package com.qf.day15_actionbar_demo4.fragment;
  
  import java.util.List;
  
  import com.qf.day15_actionbar_demo4.R;
  import com.qf.day15_actionbar_demo4.asynctask.MyTask;
  import com.qf.day15_actionbar_demo4.interface0.CallBackData;
  
  import android.app.Activity;
  import android.app.Fragment;
  import android.os.Bundle;
  import android.util.Log;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.ArrayAdapter;
  import android.widget.ListView;
  import android.widget.TextView;
  
  public class MyFragment extends Fragment{
  
      private ListView lv;
  
      int pos ;
  
      private String path,num;//请求地址 和请求数据的解析需要的对象
  
      @Override
      public void onAttach(Activity activity) {
          // TODO Auto-generated method stub
          super.onAttach(activity);
  
           pos = getArguments().getInt("pos");
           String[] paths = getResources().getStringArray(R.array.paths);
           String[] nums = getResources().getStringArray(R.array.nums);
  
           path = paths[pos];
           num = nums[pos];
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
          // TODO Auto-generated method stub
  
          View view = inflater.inflate(R.layout.layout, container, false);
  
          lv = (ListView) view.findViewById(R.id.lv);
  
          return view;
      }
  
      @Override
      public void onActivityCreated(Bundle savedInstanceState) {
          // TODO Auto-generated method stub
          super.onActivityCreated(savedInstanceState);
          //开启异步任务  请求数据  展示数据
  
          new MyTask(num, new CallBackData() {
  
              @Override
              public void sendData(List<String> list) {
                  // TODO Auto-generated method stub
                  Log.e("AAA", "===path=="+path);
                  Log.e("AAA", "===list=="+list.size());
                  ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
                          android.R.layout.simple_list_item_1, list);
  
                  lv.setAdapter(adapter);
              }
          }).execute(path);
  
      }
  
      @Override
      public void onHiddenChanged(boolean hidden) {
  
          super.onHiddenChanged(hidden);
          Log.e("AAA", "==onHiddenChanged==");
      }
  
  }
  

• 一个回调接口:

  package com.qf.day15_actionbar_demo4.interface0;
  
  import java.util.List;
  
  public interface CallBackData {
  
      public void sendData(List<String> list);
  
  }
  

• 一个网络下载代码:

package com.qf.day15_actionbar_demo4.utils;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class HttpUtils {

    public static String getStr(String path) {
        // TODO Auto-generated method stub
        HttpURLConnection connection = null;
        InputStream is  = null;
        try {
            URL url = new URL(path);

             connection= (HttpURLConnection) url.openConnection();

            connection.setRequestMethod("GET");

            connection.setConnectTimeout(5000);

            connection.connect();

            if(connection.getResponseCode()==200)
            {
                 is = connection.getInputStream();

                StringBuilder sBuilder = new StringBuilder();

                byte[] buffer = new byte[1024];
                int len = 0;

                while ((len=is.read(buffer))!=-1) {

                    sBuilder.append(new String(buffer,0,len));

                }

                return sBuilder.toString();
            }

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally
        {
            if(connection!=null)
            {
                connection.disconnect();
            }
            if (is!=null) {

                try {
                    is.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

}

• 解析json数据工具类:

  package com.qf.day15_actionbar_demo4.utils;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.HttpURLConnection;
  import java.net.MalformedURLException;
  import java.net.URL;
  
  public class HttpUtils {
  
      public static String getStr(String path) {
          // TODO Auto-generated method stub
          HttpURLConnection connection = null;
          InputStream is  = null;
          try {
              URL url = new URL(path);
  
               connection= (HttpURLConnection) url.openConnection();
  
              connection.setRequestMethod("GET");
  
              connection.setConnectTimeout(5000);
  
              connection.connect();
  
              if(connection.getResponseCode()==200)
              {
                   is = connection.getInputStream();
  
                  StringBuilder sBuilder = new StringBuilder();
  
                  byte[] buffer = new byte[1024];
                  int len = 0;
  
                  while ((len=is.read(buffer))!=-1) {
  
                      sBuilder.append(new String(buffer,0,len));
  
                  }
  
                  return sBuilder.toString();
              }
  
          } catch (Exception e) {
              // TODO Auto-generated catch block
              e.printStackTrace();
          }finally
          {
              if(connection!=null)
              {
                  connection.disconnect();
              }
              if (is!=null) {
  
                  try {
                      is.close();
                  } catch (IOException e) {
                      // TODO Auto-generated catch block
                      e.printStackTrace();
                  }
              }
          }
          return null;
      }
  
  }