Android实现ViewPager无限循环效果（一）

package com.xiaomai.myproject.demo;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.view.ViewPager;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import com.xiaomai.myproject.R;
import com.xiaomai.myproject.adapter.LoopViewPagerAdapter;
import com.xiaomai.myproject.base.BaseActivity;
import com.xiaomai.myproject.utils.Utils;
import java.util.ArrayList;
import java.util.List;
/**
* Created by XiaoMai on 2016/10/7 17:19.
* 
*/
public class LoopViewPagerDemoActivity extends BaseActivity {
/**
* 更新图片的时间
*/
private static final int UPDATE_TIME = 3 * 1000;
private ViewPager mViewPager;
private LoopViewPagerAdapter mLoopViewPager;
/**
* 图片资源集合
*/
private int[] mImageIds;
/**
* 图片集合
*/
private List<ImageView  mImageList;
/**
* 当前广告的index
*/
private int mCurrentPageIndex;
/**
* 指示Point
*/
private LinearLayout mLinearLayoutPoints;
private Handler mHandler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
protected void onResume() {
super.onResume();
mHandler.postDelayed(myRunnable, UPDATE_TIME);
}
@Override
protected void onPause() {
super.onPause();
mHandler.removeCallbacks(myRunnable);
}
Runnable myRunnable = new Runnable() {
@Override
public void run() {
mViewPager.setCurrentItem(mCurrentPageIndex + 1);
}
};
@Override
protected void initVariables() {
super.initVariables();
}
@Override
protected void initViews() {
mLinearLayoutPoints = (LinearLayout) findViewById(R.id.activity_ll_container);
mViewPager = (ViewPager) findViewById(R.id.activity_loop_viewpager);
}
@Override
protected void loadData() {
super.loadData();
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
/**
* 初始化图片的资源id
*/
mImageIds = new int[]{
R.mipmap.ic_launcher,
R.mipmap.ic_launcher,
R.drawable.my_toast,
R.drawable.my_toast};
/**
* 添加ImageView
*/
mImageList = new ArrayList< ();
//额外添加两张图片
int pagerCount = mImageIds.length + 2;
ViewGroup.LayoutParams layoutParams =
new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
for (int i = 0; i < pagerCount; i++) {
ImageView imageView = new ImageView(mContext);
imageView.setLayoutParams(layoutParams);
mImageList.add(imageView);
}
//圆点的直径
int diameter = Utils.dip2px(mContext,10f);
LinearLayout.LayoutParams params =
new LinearLayout.LayoutParams(diameter, diameter);
int margin = Utils.dip2px(mContext,5f);
params.setMargins(margin,margin,margin,margin);
mLinearLayoutPoints.removeAllViews();
for (int i = 0; i < mImageList.size(); i++) {
View view = new View(mContext);
view.setLayoutParams(params);
if (i != 0 && i != mImageList.size() - 1) {
view.setBackgroundResource(R.drawable.circle_normal);
}
mLinearLayoutPoints.addView(view);
}
mLinearLayoutPoints.setVisibility(View.VISIBLE);
mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
mHandler.removeCallbacks(myRunnable);
mHandler.postDelayed(myRunnable, UPDATE_TIME);
mCurrentPageIndex = position;
if (position == 0) {
// 当视图在第一个时，将页面号设置为图片的最后一张。
mCurrentPageIndex = mImageIds.length;
} else if (position == mImageIds.length + 1) {
// 当视图在最后一个时,将页面号设置为图片的第一张。
mCurrentPageIndex = 1;
} else {
}
/**
* 当视图在第一个或者最后一个时，pageIndex和position的值不相等，
* 所以要改变viewPager的当前item。
*/
if (position != mCurrentPageIndex) {
/**
* 第二参数必须设置为false，意思是立即过渡，不给用户视觉上的效果。
*/
mViewPager.setCurrentItem(mCurrentPageIndex, false);
return;
}
for (int i = 1; i < mLinearLayoutPoints.getChildCount() - 1; i++) {
if (i != mCurrentPageIndex){
mLinearLayoutPoints.getChildAt(i).setBackgroundResource(R.drawable.circle_normal);
}else {
mLinearLayoutPoints.getChildAt(mCurrentPageIndex).setBackgroundResource(
R.drawable.circle_select);
}
}
}
@Override
public void onPageScrollStateChanged(int state) {
}
});
/**
* 当ViewPager被按下的时候，取消自动滚动
* 反之开启自动滑动。
*/
mViewPager.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction() == MotionEvent.ACTION_DOWN){
mHandler.removeCallbacks(myRunnable);
}else if (event.getAction() == MotionEvent.ACTION_UP){
mHandler.postDelayed(myRunnable, UPDATE_TIME);
}
return false;
}
});
mLoopViewPager = new LoopViewPagerAdapter(mImageList, mImageIds);
mViewPager.setAdapter(mLoopViewPager);
/**
* 因为第0个item是另外添加的那张图片，所以初始化时要把当前item设置为1。
*/
mViewPager.setCurrentItem(1);
dissMissProgressDialog();
}
}, 3 * 1000);
}
@Override
protected int getContentLayout() {
return R.layout.act_loopviewpager;
}
}

package com.xiaomai.myproject.adapter;
import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import java.util.List;
/**
* Created by XiaoMai on 2016/10/7 17:23.
*/
public class LoopViewPagerAdapter extends PagerAdapter {
private List<ImageView  mImageList;
private int[] mImageIds;
public LoopViewPagerAdapter(List<ImageView  mImageList, int[] mImageIds) {
this.mImageList = mImageList;
this.mImageIds = mImageIds;
}
@Override
public int getCount() {
return mImageList == null ? 0 : mImageList.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
if (position == 0) {
// 如果是第0个item就设置它的图片内容为最后一个图片的内容
mImageList.get(position).setImageResource(mImageIds[mImageIds.length-1]);
} else if (position == (mImageList.size() - 1)) {
// 如果是最后一个item就设置它的图片内容为第一个图片的内容
mImageList.get(position).setImageResource(mImageIds[0]);
} else {
// 这是正常的图片
mImageList.get(position).setImageResource(mImageIds[position - 1]);
}
container.addView(mImageList.get(position));
return mImageList.get(position);
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView(mImageList.get(position));
}
}

<?xml version="1.0" encoding="utf-8"? 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" 
<include
android:id="@+id/titleBar"
layout="@layout/my_app_bar" / 
<android.support.v4.view.ViewPager
android:id="@+id/activity_loop_viewpager"
android:layout_width="match_parent"
android:layout_height="200dp"
android:layout_below="@id/titleBar" / 
<LinearLayout
android:id="@+id/activity_ll_container"
android:layout_width="match_parent"
android:orientation="horizontal"
android:gravity="center"
android:background="@color/toast"
android:layout_alignBottom="@id/activity_loop_viewpager"
android:visibility="gone"
android:layout_height="40dp"/ 
</RelativeLayout