android中viewPager实现的屏幕左右切换(入门篇)

大多数的APP都可以实现几个屏幕来回的切换，

首先新建两个Activity，内容随意，布局随意。接下来在MainActivity.xml：

 <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"
     tools:context=".MainActivity" >

     <android.support.v4.view.ViewPager
         android:id="@+id/viewpager"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content" >
     </android.support.v4.view.ViewPager>

 </RelativeLayou

不要忘记android-support-v4包，目前4.0以上版本都自带

接下来是java中的方法：

 protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         viewPager = (ViewPager) findViewById(R.id.viewpager);
         View view1 = LayoutInflater.from(MainActivity.this).inflate(R.layout.a,
                 null);
         View view2 = LayoutInflater.from(MainActivity.this).inflate(R.layout.b,
                 null);
         list = new ArrayList<View>();
         list.add(view1);
         list.add(view2);
         viewPager.setAdapter(new MyAdapter());
     }

 class MyAdapter extends PagerAdapter {

         @Override
         public int getCount() {
             return list.size();
         }

         @Override
         public boolean isViewFromObject(View arg0, Object arg1) {
             return arg0 == arg1;
         }

         @Override
         public CharSequence getPageTitle(int position) {
             return titlelist.get(position);

         }

         @Override
         public Object instantiateItem(View container, int position) {
             ((ViewPager) container).addView(list.get(position));
             return list.get(position);
         }

         @Override
         public void destroyItem(View container, int position, Object object) {
             super.destroyItem(container, position, object);
             ((ViewPager) container).removeView(list.get(position));
         }
     }

至此就可以实现两个屏幕的切换