android中viewPager+fragment实现的屏幕左右切换(进阶篇)_移动开发_编程开发_程序员俱乐部

Fragment支持在不同的Activity中使用并且可以处理自己的输入事件以及生命周期方法等。可以看做是一个子Activity。

先看一下布局：

 1 <LinearLayout 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     tools:context=".ViewPagerActivity" >
 6 
 7     <android.support.v4.view.ViewPager
 8         android:id="@+id/viewpager"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content"
11         android:layout_gravity="center" >
12     </android.support.v4.view.ViewPager>
13 
14 </LinearLayout>

主文件：ViewPagerActivity继承FragmentActivity

 1 package com.example.viewpagerdemo;
 2 
 3 import java.util.ArrayList;
 4 import java.util.List;
 5 
 6 import android.os.Bundle;
 7 import android.support.v4.app.Fragment;
 8 import android.support.v4.app.FragmentActivity;
 9 import android.support.v4.view.ViewPager;
10 
11 import com.example.adapter.fragmentAdapter;
12 
13 public class ViewPagerActivity extends FragmentActivity {
14 
15     @Override
16     protected void onCreate(Bundle savedInstanceState) {
17         super.onCreate(savedInstanceState);
18         setContentView(R.layout.activity_view_pager);
19         List<Fragment> fragments = new ArrayList<Fragment>();
20         for (int i = 0; i < 3; i++) {
21             Fragment f = new ButtonFragment();
22             fragments.add(f);
23         }
24         ViewPager vp = (ViewPager) findViewById(R.id.viewpager);
25         fragmentAdapter fa = new fragmentAdapter(getSupportFragmentManager(),
26                 fragments);
27         vp.setAdapter(fa);
28         vp.setCurrentItem(0);
29     }
30 }

新建fragmentAdapter继承FragmentPagerAdapter并未写出实现的方法

 1 package com.example.adapter;
 2 
 3 import java.util.List;
 4 
 5 import android.support.v4.app.Fragment;
 6 import android.support.v4.app.FragmentManager;
 7 import android.support.v4.app.FragmentPagerAdapter;
 8 
 9 public class fragmentAdapter extends FragmentPagerAdapter {
10     private List<Fragment> fragments;
11     private FragmentManager fm;
12 
13     public fragmentAdapter(FragmentManager fm, List<Fragment> fragments) {
14         super(fm);
15         this.fragments = fragments;
16 
17     }
18 
19     public fragmentAdapter(FragmentManager fm) {
20         super(fm);
21         this.fm = fm;
22     }
23 
24     @Override
25     public Fragment getItem(int arg0) {
26         return fragments.get(arg0);
27     }
28 
29     @Override
30     public int getCount() {
31         return fragments.size();
32     }
33 
34 }

定义要展示的fragment内容，在这只放一个Button

 1 package com.example.viewpagerdemo;
 2 
 3 import android.os.Bundle;
 4 import android.support.v4.app.Fragment;
 5 import android.view.LayoutInflater;
 6 import android.view.View;
 7 import android.view.ViewGroup;
 8 import android.widget.TextView;
 9 
10 public class ButtonFragment extends Fragment {11     private View rootView;
12
13     @Override
14     public View onCreateView(LayoutInflater inflater, ViewGroup container,
15             Bundle savedInstanceState) {
16         rootView = inflater.inflate(R.layout.guide1, container, false);
17         return rootView;
18     }
19 }

至此实现3个含有Button可以左右切换了