android ViewPager

ViewPager类提供了多界面切换的新效果。新效果有以下特征：

[1] 当前显示一组界面中的其中一个界面。

[2] 当用户经过左右滑动界面时，当前的屏幕显示当前界面和下一个界面的一部分。

[3]滑动结束后，界面自动跳转到当前选择的界面中

ViewPager用于实现多页面的切换效果，该类存在于Google的兼容包里面，因此在引用时记得在BuilldPath中加入“android-support-v4.jar”

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

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

        <android.support.v4.view.PagerTitleStrip
            android:id="@+id/pagertitle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="top" />
    </android.support.v4.view.ViewPager>

</LinearLayout>

其中ViewPager为多页显示控件，PagerTitleStrip用于显示当前页面的标题

package com.test

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.PagerTitleStrip;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;

public class PagerTitleDemoActivity extends Activity {
    /** Called when the activity is first created. */
	private ViewPager mViewPager;
	private PagerTitleStrip mPagerTitleStrip;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mViewPager = (ViewPager)findViewById(R.id.viewpager);
        mPagerTitleStrip = (PagerTitleStrip)findViewById(R.id.pagertitle);
        
        //将要分页显示的View装入数组中
        LayoutInflater mLi = LayoutInflater.from(this);
        View view1 = mLi.inflate(R.layout.view1, null);
        View view2 = mLi.inflate(R.layout.view2, null);
        View view3 = mLi.inflate(R.layout.view3, null);
        
        //每一个页面的Title数据
        final ArrayList<View> views = new ArrayList<View>();
        views.add(view1);
        views.add(view2);
        views.add(view3);
        
        final ArrayList<String> titles = new ArrayList<String>();
        titles.add("tab1");
        titles.add("tab2");
        titles.add("tab3");
        
        //填充ViewPager的数据适配器
        PagerAdapter mPagerAdapter = new PagerAdapter() {
			
			@Override
			public boolean isViewFromObject(View arg0, Object arg1) {
				return arg0 == arg1;
			}
			
			@Override
			public int getCount() {
				return views.size();
			}

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

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

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