Android ViewPager的使用以及定时切换实现

ViewPager的页面布局如下：

<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<FrameLayout
android:layout_width="fill_parent"
android:layout_height="200dp">

<android.support.v4.view.ViewPager
android:id="@+id/myviewpager"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="35dp"
android:orientation="vertical"
android:layout_gravity="bottom"
android:gravity="center"
android:background="#33000000">

<TextView
android:id="@+id/txttitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="@android:color/white"
/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="3dp"
android:orientation="horizontal">

<View
android:id="@+id/dotnumber_1"
android:layout_width="5dp"
android:layout_height="5dp"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:background="@drawable/mydotfocus"
/>
<View
android:id="@+id/dotnumber_2"
android:layout_width="5dp"
android:layout_height="5dp"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:background="@drawable/mydotnormal"
/>
<View
android:id="@+id/dotnumber_3"
android:layout_width="5dp"
android:layout_height="5dp"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:background="@drawable/mydotnormal"
/>
<View
android:id="@+id/dotnumber_4"
android:layout_width="5dp"
android:layout_height="5dp"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:background="@drawable/mydotnormal"
/>
<View
android:id="@+id/dotnumber_5"
android:layout_width="5dp"
android:layout_height="5dp"
android:layout_marginLeft="2dp"
android:layout_marginRight="2dp"
android:background="@drawable/mydotnormal"
/>

</LinearLayout>

</LinearLayout>
</FrameLayout>

</RelativeLayout>

包括文字和浮点的切换以及图片的切换，效果图如下：



viewpager的实现要设置一个VewPagerAdapter 还有 一个 OnViewPagerChanged()的监听事件代码如下:

package com.shao.ViewPagerLearn;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends Activity {

private int[] imageids;
private String[] titles;
private List<ImageView> imageslist;
private List<View>  dotslist;
private TextView  txttitle;
private ViewPager mViewPager;
private ScheduledExecutorService  excutorservice;

private int oldposition;
private int currentposition;
private Handler handle = new Handler(){

@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);

mViewPager.setCurrentItem(currentposition);
}

};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageids = new int[]{R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e};
titles = new String[]{"巩俐不低俗，我就不能低俗","扑树又回来啦！再唱经典老歌引万人大合唱",	"揭秘北京电影如何升级",
"乐视网TV版大派送",
"热血屌丝的反杀"};
imageslist = new ArrayList<ImageView>();
for(int i = 0; i < imageids.length;i++)
{
ImageView imageview = new ImageView(getApplicationContext());
imageview.setBackgroundResource(imageids[i]);
imageslist.add(imageview);

}

dotslist = new ArrayList<View>();
dotslist.add(findViewById(R.id.dotnumber_1));
dotslist.add(findViewById(R.id.dotnumber_2));
dotslist.add(findViewById(R.id.dotnumber_3));
dotslist.add(findViewById(R.id.dotnumber_4));
dotslist.add(findViewById(R.id.dotnumber_5));

txttitle = (TextView)findViewById(R.id.txttitle);
txttitle.setText(titles[0]);

mViewPager = (ViewPager)findViewById(R.id.myviewpager);
mViewPager.setAdapter(new MyViewpagerAdaper());

//创建一个页面更换监听
mViewPager.setOnPageChangeListener(new OnPageChangeListener() {

@Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
txttitle.setText(titles[arg0]);

dotslist.get(oldposition).setBackgroundResource(R.drawable.mydotnormal);
dotslist.get(arg0).setBackgroundResource(R.drawable.mydotfocus);

oldposition = arg0;
currentposition = arg0;
}

@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
// TODO Auto-generated method stub

}

@Override
public void onPageScrollStateChanged(int arg0) {
// TODO Auto-generated method stub

}
});

}

private class MyViewpagerAdaper  extends PagerAdapter
{

@Override
public int getCount() {
// TODO Auto-generated method stub
return imageids.length;
}

//判断是不是同一张图片
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
// TODO Auto-generated method stub
return arg0 == arg1;
}

/*显示内存就放三张图片 滑动的时候 出去的图片执行destroy 进到内存的图片就是instaint*/

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
// TODO Auto-generated method stub
//super.destroyItem(container, position, object);

//移除这个位置的图片
container.removeView(imageslist.get(position));

}

@Override
public Object instantiateItem(ViewGroup container, int position) {
// TODO Auto-generated method stub
container.addView(imageslist.get(position));
return imageslist.get(position);
}

}

@Override
protected void onStart() {
// TODO Auto-generated method stub
excutorservice = Executors.newSingleThreadScheduledExecutor();
excutorservice.scheduleWithFixedDelay(new MyTask(), 2, 2, TimeUnit.SECONDS);

super.onStart();
}

private class MyTask implements Runnable
{

@Override
public void run() {
// TODO Auto-generated method stub
//当前图片+1进行图片的切换
currentposition = (currentposition + 1)%imageids.length;
handle.sendEmptyMessage(0);

}

}

@Override
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

创建一个newSingleThreadScheduledExecutor进行图片的切换效果