ViewPager实现循环滑动实现方法+定时自动滑动实现方法详解

最新推荐文章于 2020-06-13 20:14:50 发布

原创最新推荐文章于 2020-06-13 20:14:50 发布 · 1.7k 阅读

0 ·

CC 4.0 BY-SA版权

Android开发专栏收录该内容

30 篇文章

订阅专栏

本文介绍如何使用ViewPager实现带有三个广告页的循环滑动效果，并加入定时自动切换及用户触控滑动功能。此外，还实现了点击广告跳转到对应网址的功能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

ViewPager实现循环滑动实现方法+定时自动滑动实现方法详解

要实现如下效果顶部有一行广告条，包含三页每过一段时间自动显示下一个广告页，当前显示最后一页广告的时候下一页是第一页。另外支持用户手段滑动（左右无限滑动，当前是第一页的时候往左滑动，显示最后一下，当前是最后一页的时候往右滑动显示第一页）。点击广告条的时候，打开指定网页。

实现方法的思路：有3个页面（ABC），则我们提供5也页面（XABCY其中X和Y没有任何实际意义）给Pager的Adapter

Fragment中的关键代码：

private ViewPager mAdPager = null;//定义pager

private int mCurrentAdPageIndex = 1 ;//用于记录当前page的页码

privateImageView[] mAdIndicatorImageViews = null ;//用于标记当前是在哪个页面的图标，这里用五角星，高亮表示选中

private Handler mUiHandler = null ; //用于实现timer

privateAdItemClickListener mAdItemClickListener = null ;//点击事件监听器

private voidinitAdPager() {

ViewGroup group =(ViewGroup) getActivity()

.findViewById(R.id.viewGroup) ;

mAdItemClickListener = newAdItemClickListener() ;

//存放的是三张广告背景img1 img2 img3

List<View> advPics = newArrayList<View>() ;

ImageView img1 = newImageView(getActivity()) ;

img1.setBackgroundResource(R.drawable.ad_1) ;

img1.setOnClickListener(mAdItemClickListener) ;

img1.setTag("http://www.baidu.com") ;

ImageView img2 = newImageView(getActivity()) ;

img2.setBackgroundResource(R.drawable.ad_2) ;

img2.setOnClickListener(mAdItemClickListener) ;

img2.setTag("http://www.163.com") ;

ImageView img3 = newImageView(getActivity()) ;

img3.setBackgroundResource(R.drawable.ad_3) ;

img3.setOnClickListener(mAdItemClickListener) ;

img3.setTag("http://www.qq.com") ;

// img1 img2 img3 循环滑动

// img0 img1img2 img3 img4

ImageView img0 = newImageView(getActivity()) ;

ImageView img4 = newImageView(getActivity()) ;

advPics.add(img0) ;

advPics.add(img1) ;

advPics.add(img2) ;

advPics.add(img3) ;

advPics.add(img4) ;

// 对imageviews进行填充

mAdIndicatorImageViews = newImageView[advPics.size() - 2] ;

// 小图标

for (int i = 0; i < advPics.size() -2; i++) {

ImageView imageView = newImageView(getActivity()) ;

LinearLayout.LayoutParams lp = newLinearLayout.LayoutParams(20,20);

lp.setMargins(0,0, 20, 0);//modify 20 to a suitable value

imageView.setLayoutParams(lp) ;

mAdIndicatorImageViews[i] = imageView ;

if (i == 0) {

mAdIndicatorImageViews[i]

.setBackgroundResource(R.drawable.music_handle_favorites_select_icon) ;

} else {

mAdIndicatorImageViews[i]

.setBackgroundResource(R.drawable.music_handle_favorites_normal_icon) ;

}

group.addView(mAdIndicatorImageViews[i]) ;

}

mAdPager =(ViewPager) getActivity().findViewById(R.id.adv_pager) ;

mAdPager.setOffscreenPageLimit(5);

mAdPager.setAdapter(newAdvAdapter(advPics)) ;

mAdPager.setOnPageChangeListener(newAdPageChangeListener()) ;

mAdPager.setOnTouchListener(newOnTouchListener() {

@Override

public booleanonTouch(View v, MotionEvent event) {

switch (event.getAction()){

caseMotionEvent.ACTION_DOWN:

case MotionEvent.ACTION_MOVE:

//Log.d(TAG,"onTouch down or move") ;

pauseShowNextAdPageDelay() ;

break ;

caseMotionEvent.ACTION_UP:

showNextAdPageDelay() ;

//Log.d(TAG,"onTouch up") ;

break ;

default:

break ;

}

return false ;

}

}) ;

mAdPager.setCurrentItem(mCurrentAdPageIndex, false) ;

showNextAdPageDelay() ;

}

private Runnable mShowAdNextRunnable = newRunnable() {

@Override

public void run() {

int index = ++mCurrentAdPageIndex % (mAdIndicatorImageViews.length + 1) ;

if(index == 0) {

mCurrentAdPageIndex = 1;

index = 1;

}

mAdPager.setCurrentItem(index, false) ;

showNextAdPageDelay() ;

}

} ;

private voidshowNextAdPageDelay() {

mUiHandler.postDelayed(mShowAdNextRunnable, 4500) ;

}

private voidpauseShowNextAdPageDelay() {

mUiHandler.removeCallbacks(mShowAdNextRunnable) ;

}

private classAdItemClickListener implements OnClickListener {

@Override

public voidonClick(View v) {

Object tag = v.getTag();

Log.d(TAG, "onClick()") ;

if (!(tag instanceof String)){

Log.d(TAG, "tagis not a string") ;

return ;

}

String url =(String) tag ;

if ("".equals(url)) {

Log.d(TAG, "urlis empty") ;

return ;

}

openBrowserWithUrl(url) ;

}

private voidopenBrowserWithUrl(String url) {

Intent intent = newIntent(Intent.ACTION_VIEW) ;

intent.setData(Uri.parse(url)) ;

startActivity(intent) ;

}

private final classAdPageChangeListener implements OnPageChangeListener{

boolean mIsAutoScrolled = false ;

@Override

public voidonPageScrollStateChanged(int arg0) {

Log.d(TAG, "onPageScrollStateChangedarg0 = " + arg0 + ", currentIdex = " + mAdPager.getCurrentItem());

switch (arg0) {

caseViewPager.SCROLL_STATE_DRAGGING:// 手势滑动

mIsAutoScrolled = false ;

break ;

caseViewPager.SCROLL_STATE_SETTLING:// 界面切换

mIsAutoScrolled = true ;

break ;

caseViewPager.SCROLL_STATE_IDLE:

if (mAdPager.getCurrentItem()== mAdPager.getAdapter()

.getCount() - 2&& !mIsAutoScrolled) {

mAdPager.setCurrentItem(1);

return ;

}

if (mAdPager.getCurrentItem()== 1 && !mIsAutoScrolled) {

mAdPager.setCurrentItem(mAdPager.getAdapter()

.getCount() -2) ;

return ;

}

break ;

default:

break ;

}

@Override

public voidonPageScrolled(int arg0, float arg1, int arg2) {

}

@Override

public voidonPageSelected(int arg0) {

Log.d(TAG, "onPageSelected: " + arg0);

for (int i = 0; i < mAdIndicatorImageViews.length; i++) {

mAdIndicatorImageViews[i]

.setBackgroundResource(R.drawable.music_handle_favorites_normal_icon) ;

}

if(arg0 > mAdIndicatorImageViews.length) {

Log.d(TAG, "setCurrentItem" + 1);

mAdPager.setCurrentItem(1,false) ;

mAdIndicatorImageViews[1 - 1]

.setBackgroundResource(R.drawable.music_handle_favorites_select_icon) ;

}else if(arg0 < 1) {

Log.d(TAG, "setCurrentItem" + mAdIndicatorImageViews.length);

mAdPager.setCurrentItem(mAdIndicatorImageViews.length, false) ;

mAdIndicatorImageViews[mAdIndicatorImageViews.length - 1]

.setBackgroundResource(R.drawable.music_handle_favorites_select_icon) ;

}else {

Log.d(TAG, "setCurrentItem" + arg0);

//mAdPager.setCurrentItem(arg0,false) ;

mAdIndicatorImageViews[arg0 - 1]

.setBackgroundResource(R.drawable.music_handle_favorites_select_icon) ;

}

private final classAdvAdapter extends PagerAdapter {

privateList<View> views = null ;

publicAdvAdapter(List<View> views) {

this.views = views ;

}

@Override

public voiddestroyItem(View arg0, int arg1, Object arg2) {

((ViewPager) arg0).removeView(views.get(arg1)) ;

}

@Override

public voidfinishUpdate(View arg0) {

}

@Override

public intgetCount() {

return views.size() ;

}

@Override

public ObjectinstantiateItem(View arg0, int arg1) {

Log.d(TAG, "instantiateItem:" + arg1);

//((ViewPager)arg0).removeView(views.get(arg1)) ;

((ViewPager) arg0).addView(views.get(arg1), 0) ;

return views.get(arg1) ;

}

@Override

public booleanisViewFromObject(View arg0, Object arg1) {

return arg0 == arg1 ;

}

@Override

public voidrestoreState(Parcelable arg0, ClassLoader arg1) {

}

@Override

publicParcelable saveState() {

return null ;

}

@Override

public voidstartUpdate(View arg0) {

}

Xml file

<?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/adv_pager"

android:layout_width="match_parent"

android:layout_height="0dp"

android:layout_weight="2"

android:background="@drawable/ad_migu1">

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

<LinearLayout

android:id="@+id/viewGroup"

android:layout_width="fill_parent"

android:layout_height="10dp"

android:layout_marginTop="-10dp"

android:gravity="center"

android:orientation="horizontal">

</LinearLayout>

<GridView

android:id="@id/chart_grid"

android:layout_width="fill_parent"

android:layout_height="0dp"

android:layout_marginLeft="10dip"

android:layout_marginRight="10dip"

android:layout_weight="7"

android:numColumns="2"/>

<TextView

android:id="@id/empty_view"

android:layout_width="fill_parent"

android:layout_height="match_parent"

android:gravity="center"

android:text="@string/text_empty_view"

android:textColor="@color/list_view_empty_view_text_color"/>

</LinearLayout>