Android成长日记-使用PagerAdapter实现页面切换

Tip：此方式可以实现页面切换

1. 创建view1.xml,view2.xml,view3.xml,main.xml

在main.xml中创建

<android.support.v4.view.ViewPager

android:id="@+id/pager"

android:layout_width="wrap_content"

android:layout_height="wrap_content">

</android.support.v4.view.ViewPager>

2. 创建MainActivity.java

public class MainActivity extends Activity {

private List<View>viewList;[s1]

private ViewPager Pager;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

viewList=new ArrayList<View>();

Pager=(ViewPager) findViewById(R.id.pager);[s2]

//将布局转化为视图

View view1=View.inflate(this, R.layout.view1,null);

View view2=View.inflate(this, R.layout.view2, null);

View view3=View.inflate(this, R.layout.view3, null);[s3]

viewList.add(view1);

viewList.add(view2);

viewList.add(view3);[s4]

//创建PagerAdapter适配器

MyViewPagerAdapter adapter=new MyViewPagerAdapter(viewList);

//ViewPager加载适配器

Pager.setAdapter(adapter);

}

}

3. 创建适配器MyViewPagerAdapter.java

public class MyViewPagerAdapter extends PagerAdapter {

private List<View>viewList;[s5]

public MyViewPagerAdapter(List<View> viewList)

{

this.viewList=viewList;

}[s6]

@Override

public int getCount() {

//返回页卡的数量

return viewList.size();

}

@Override

public boolean isViewFromObject(View arg0, Object arg1) {

// View是否来自于对象

return arg0==arg1;

}

@Override

public Object instantiateItem(ViewGroup container, int position) {[s7]

// 实例化一个页卡

container.addView(viewList.get(position));

return viewList.get(position);

}

@Override

public void destroyItem(ViewGroup container, int position, Object object) {[s8]

//销毁一个页卡

container.removeView(viewList.get(position));

}[s9]

---

[s1]创建集合List，泛型为View

[s2]控件实例化

[s3]将布局转换为视图

[s4]添加到集合

[s5]声明List集合

[s6]创建构造方法，用于接收传来的集合

[s7]实例化页卡

[s8]销毁页卡

[s9]新增的两个方法