7、窗口导航

  1 import java.util.Locale;
  2 
  3 import android.os.Bundle;
  4 import android.support.v4.app.Fragment;
  5 import android.support.v4.app.FragmentActivity;
  6 import android.support.v4.app.FragmentManager;
  7 import android.support.v4.app.FragmentPagerAdapter;
  8 import android.support.v4.view.ViewPager;
  9 import android.view.LayoutInflater;
 10 import android.view.Menu;
 11 import android.view.View;
 12 import android.view.ViewGroup;
 13 import android.widget.TextView;
 14 
 15 public class MainActivity extends FragmentActivity {
 16 
 17     /**  
 18      * The {@link android.support.v4.view.PagerAdapter} that will provide
 19      * fragments for each of the sections. We use a
 20      * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
 21      * will keep every loaded fragment in memory. If this becomes too memory
 22      * intensive, it may be best to switch to a
 23      * {@link android.support.v4.app.FragmentStatePagerAdapter}.
 24      */
 25     SectionsPagerAdapter mSectionsPagerAdapter;
 26 
 27     /**
 28      * The {@link ViewPager} that will host the section contents.
 29      */
 30     ViewPager mViewPager;
 31 
 32     @Override
 33     protected void onCreate(Bundle savedInstanceState) {
 34         super.onCreate(savedInstanceState);
 35         setContentView(R.layout.activity_main);
 36         // Create the adapter that will return a fragment for each of the three
 37         // primary sections of the app.
 38         mSectionsPagerAdapter = new SectionsPagerAdapter(
 39                 getSupportFragmentManager());
 40         
 41 
 42         // Set up the ViewPager with the sections adapter.
 43         mViewPager = (ViewPager) findViewById(R.id.pager);
 44         mViewPager.setAdapter(mSectionsPagerAdapter);
 45 
 46     }
 47 
 48     @Override
 49     public boolean onCreateOptionsMenu(Menu menu) {
 50         // Inflate the menu; this adds items to the action bar if it is present.
 51         getMenuInflater().inflate(R.menu.main, menu);
 52         return true;
 53     }
 54 
 55     /**
 56      * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 57      * one of the sections/tabs/pages.
 58      */
 59     public class SectionsPagerAdapter extends FragmentPagerAdapter {
 60 
 61         public SectionsPagerAdapter(FragmentManager fm) {
 62             super(fm);
 63         }
 64 
 65         @Override
 66         public Fragment getItem(int position) {
 67             // getItem is called to instantiate the fragment for the given page.
 68             // Return a DummySectionFragment (defined as a static inner class
 69             // below) with the page number as its lone argument.
 70             Fragment fragment = new DummySectionFragment();
 71             Bundle args = new Bundle();
 72             args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
 73             fragment.setArguments(args);
 74             return fragment;
 75         }
 76 
 77         @Override
 78         public int getCount() {
 79             // Show 3 total pages.
 80             return 3;
 81         }
 82 
 83         @Override
 84         public CharSequence getPageTitle(int position) {
 85             Locale l = Locale.getDefault();
 86             switch (position) {
 87             case 0:
 88                 return getString(R.string.title_section1).toUpperCase(l);
 89             case 1:
 90                 return getString(R.string.title_section2).toUpperCase(l);
 91             case 2:
 92                 return getString(R.string.title_section3).toUpperCase(l);
 93             }
 94             return null;
 95         }
 96     }
 97 
 98     /**
 99      * A dummy fragment representing a section of the app, but that simply
100      * displays dummy text.
101      */
102     public static class DummySectionFragment extends Fragment {
103         /**
104          * The fragment argument representing the section number for this
105          * fragment.
106          */
107         public static final String ARG_SECTION_NUMBER = "section_number";
108 
109         public DummySectionFragment() {
110         }
111 
112         @Override
113         public View onCreateView(LayoutInflater inflater, ViewGroup container,
114                 Bundle savedInstanceState) {
115             View rootView = inflater.inflate(R.layout.fragment_main_dummy,
116                     container, false);
117             
118             TextView dummyTextView = (TextView) rootView
119                     .findViewById(R.id.section_label);
120             dummyTextView.setText(Integer.toString(getArguments().getInt(
121                     ARG_SECTION_NUMBER)));
122             return rootView;
123         }
124     }
125 
126 }

 1 <android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:id="@+id/pager"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     tools:context=".MainActivity" >
 7 
 8     <!--
 9          This title strip will display the currently visible page title, as well as the page
10          titles for adjacent pages.
11     
12          R.layout.activity_main
13     -->
14 
15     <android.support.v4.view.PagerTitleStrip
16         android:id="@+id/pager_title_strip"
17         android:layout_width="match_parent"
18         android:layout_height="wrap_content"
19         android:layout_gravity="top"
20         android:background="#33b5e5"
21         android:paddingBottom="4dp"
22         android:paddingTop="4dp"
23         android:textColor="#fff" />
24 
25 </android.support.v4.view.ViewPager>

 1 <menu xmlns:android="http://schemas.android.com/apk/res/android" >
 2     <!--
 3          R.menu.main
 4     -->
 5     <item
 6         android:id="@+id/action_settings"
 7         android:orderInCategory="100"
 8         android:showAsAction="never"
 9         android:title="@string/action_settings"/>
10 </menu>

1 <?xml version="1.0" encoding="utf-8"?>
2 <resources>
3     <string name="app_name">MultiPageNavigation</string>
4     <string name="action_settings">Settings</string>
5     <string name="title_section1">Section 1</string>
6     <string name="title_section2">Section 2</string>
7     <string name="title_section3">Section 3</string>
8 </resources>

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:paddingBottom="@dimen/activity_vertical_margin"
 6     android:paddingLeft="@dimen/activity_horizontal_margin"
 7     android:paddingRight="@dimen/activity_horizontal_margin"
 8     android:paddingTop="@dimen/activity_vertical_margin"
 9     tools:context=".MainActivity$DummySectionFragment" >
10 <!-- 
11      R.layout.fragment_main_dummy
12  -->
13     <TextView
14         android:id="@+id/section_label"
15         android:layout_width="wrap_content"
16         android:layout_height="wrap_content" />
17 
18 </RelativeLayout>

 1 import android.app.Activity;
 2 import android.app.FragmentManager;
 3 import android.app.FragmentManager.OnBackStackChangedListener;
 4 import android.app.FragmentTransaction;
 5 import android.os.Bundle;
 6 import android.view.View;
 7 
 8 public class FragmentNavigationActivity extends Activity implements
 9         OnBackStackChangedListener {
10 
11     private void nextFragment(boolean backStackFlag) {
12         try {
13             FragmentManager fragmentManager = getFragmentManager();
14 
15             FragmentTransaction fragmentTransaction = fragmentManager
16                     .beginTransaction();
17             FragmentPage fragment = new FragmentPage();
18             fragmentTransaction.add(R.id.fragment_container, fragment);
19 
20             if (backStackFlag)
21                 fragmentTransaction
22                         .addToBackStack(String.valueOf(getFragmentManager()
23                                 .getBackStackEntryCount() + 1));
24             fragmentTransaction.commit();
25             fragmentManager.addOnBackStackChangedListener(this);
26 
27         } catch (Exception e) {  }
28     }
29 
30     @Override
31     public void onBackStackChanged() {
32         setTitle("当前第" + (getFragmentManager().getBackStackEntryCount() + 1)
33                 + "页");
34     }
35 
36     @Override
37     protected void onCreate(Bundle savedInstanceState) {
38         super.onCreate(savedInstanceState);
39         setContentView(R.layout.activity_fragment_navigation);
40         nextFragment(false);
41         onBackStackChanged();
42     }
43 
44     public void onClick_NextPage(View view) {
45         nextFragment(true);
46     }
47 
48     public void onClick_PrevPage(View view) {
49         FragmentManager fragmentManager = getFragmentManager();
50         fragmentManager.popBackStack();
51         // 将回退栈在Fragment状态全部出栈，恢复到第1页
52         // fragmentManager.popBackStackImmediate("1",FragmentManager.POP_BACK_STACK_INCLUSIVE);
53     }
54 }

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     android:layout_width="match_parent"
 3     android:layout_height="match_parent"
 4     android:orientation="vertical" >
 5 <!-- 
 6      R.layout.activity_fragment_navigation
 7  -->
 8     <LinearLayout
 9         android:layout_width="match_parent"
10         android:layout_height="wrap_content"
11         android:orientation="horizontal" >
12         <Button
13             android:layout_width="match_parent"  
14             android:layout_height="wrap_content"
15             android:onClick="onClick_PrevPage"
16             android:text="上一页" android:layout_weight="1" />
17         <Button
18             android:layout_width="match_parent"
19             android:layout_height="wrap_content"
20             android:onClick="onClick_NextPage"
21             android:text="下一页" android:layout_weight="1" />
22     </LinearLayout>
23 
24     <FrameLayout
25         android:id="@+id/fragment_container"
26         android:layout_width="match_parent"
27         android:layout_height="wrap_content" />
28 
29 </LinearLayout>

 1 import java.util.Random;
 2 import android.app.Fragment;
 3 import android.os.Bundle;
 4 import android.view.LayoutInflater;
 5 import android.view.View;
 6 import android.view.ViewGroup;
 7 import android.widget.EditText;
 8 
 9 public class FragmentPage extends Fragment {
10 
11     @Override
12     public View onCreateView(LayoutInflater inflater, ViewGroup container,
13             Bundle savedInstanceState) {
14         View view = inflater.inflate(R.layout.fragment_page, container, false);
15 
16         EditText editText = (EditText) view.findViewById(R.id.edittext);
17 
18         editText.setText(String.valueOf(Math.abs(new Random().nextLong())));
19         return view;
20     }
21 
22 }

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     android:layout_width="match_parent"
 3     android:layout_height="match_parent"
 4     android:orientation="vertical" android:background="#FFF">
 5 <!-- 
 6      R.layout.fragment_page
 7  -->
 8     <EditText
 9         android:id="@+id/edittext"
10         android:layout_width="match_parent"
11         android:layout_height="wrap_content"
12         android:text="第一页" />
13 
14 </LinearLayout>