【移动应用开发技术】怎么在Android中实现一个广告无限循环功能

【移动应用开发技术】怎么在Android中实现一个广告无限循环功能

今天就跟大家聊聊有关怎么在Android中实现一个广告无限循环功能，可能很多人都不太了解，为了让大家更加了解，在下给大家总结了以下内容，希望大家根据这篇文章可以有所收获。代码实现：public

class

NewsHomeFragment

extends

BaseFragment

implements

OnTouchListener

{

private

ImageHandler

mHandler

=

new

ImageHandler(new

WeakReference<NewsHomeFragment>(this));

private

ViewPager

mViewPager;

//

自定义轮播图的资源

private

int[]

mImageResIds

=

{

R.drawable.img1,

R.drawable.img2,

R.drawable.img3,

R.drawable.img4,

R.drawable.img5

};

//

放轮播图片的ImageView

的list

private

List<ImageView>

mImageList

=

new

ArrayList<ImageView>();

//

放圆点的View的list

private

List<View>

mDotList

=

new

ArrayList<View>();

@Override

public

View

initConvertView(LayoutInflater

inflater,

ViewGroup

container,

Bundle

savedInstanceState)

{

return

inflater.inflate(R.layout.fragment_news_main,

container,

false);

}

@Override

protected

void

onVisible(boolean

isInit)

{

if

(isInit)

{

initViews();

}

}

private

void

initViews()

{

//

初始化iewPager的内容

mViewPager

=

(ViewPager)

mConvertView.findViewById(R.id.view_pager);

LinearLayout

dotLayout

=

(LinearLayout)

mConvertView.findViewById(R.id.dotLayout);

dotLayout.removeAllViews();

for

(int

i

=

0;

i

<

mImageResIds.length;

i++)

{

ImageView

imageView

=

new

ImageView(getActivity());

imageView.setScaleType(ScaleType.FIT_XY);

//

view.setTag(mImageResId[i]);

imageView.setImageResource(mImageResIds[i]);

mImageList.add(imageView);

View

dotView

=

new

View(getActivity());

LinearLayout.LayoutParams

params

=

new

LinearLayout.LayoutParams(getResources().getDimensionPixelSize(R.dimen.dot_width),

getResources().getDimensionPixelSize(R.dimen.dot_width));

params.setMargins(4,

0,

4,

0);

dotView.setLayoutParams(params);

//

if

(i

==

0)

{

//

dotView.setBackgroundResource(R.drawable.dot_red);

//

}

else

{

//

dotView.setBackgroundResource(R.drawable.dot_gray);

//

}

dotLayout.addView(dotView);

mDotList.add(dotView);

}

mViewPager.setAdapter(new

ImageAdapter(mImageList));

mViewPager.setOnPageChangeListener(new

PageChangeListener());

mViewPager.setFocusable(true);

mViewPager.setCurrentItem(Integer.MAX_VALUE

/

2);//

默认在中间，使用户看不到边界

mViewPager.setOnTouchListener(this);

//

开始轮播效果

mHandler.sendEmptyMessageDelayed(ImageHandler.MSG_UPDATE_IMAGE,

ImageHandler.MSG_DELAY);

}

@Override

public

boolean

onTouch(View

v,

MotionEvent

event)

{

switch

(event.getAction())

{

case

MotionEvent.ACTION_DOWN:

mHandler.sendEmptyMessage(ImageHandler.MSG_KEEP_SILENT);

break;

case

MotionEvent.ACTION_UP:

case

MotionEvent.ACTION_CANCEL:

mHandler.sendEmptyMessageDelayed(ImageHandler.MSG_UPDATE_IMAGE,

ImageHandler.MSG_DELAY);

break;

}

return

false;

}

private

class

PageChangeListener

implements

OnPageChangeListener

{

//

配合Adapter的currentItem字段进行设置。

@Override

public

void

onPageSelected(int

position)

{

//

这个是设置左滑切换底部view的边界，必须要设置

App.getInstance().setBorderViewPosition(position);

mHandler.sendMessage(Message.obtain(mHandler,

ImageHandler.MSG_PAGE_CHANGED,

position,

0));

}

@Override

public

void

onPageScrolled(int

position,

float

arg1,

int

arg2)

{

}

//

覆写该方法实现轮播效果的暂停和恢复

@Override

public

void

onPageScrollStateChanged(int

state)

{

switch

(state)

{

case

ViewPager.SCROLL_STATE_DRAGGING:

mHandler.sendEmptyMessage(ImageHandler.MSG_KEEP_SILENT);

break;

case

ViewPager.SCROLL_STATE_IDLE:

mHandler.sendEmptyMessageDelayed(ImageHandler.MSG_UPDATE_IMAGE,

ImageHandler.MSG_DELAY);

break;

default:

break;

}

}

}

private

class

ImageAdapter

extends

PagerAdapter

{

private

List<ImageView>

viewlist;

public

ImageAdapter(List<ImageView>

viewlist)

{

this.viewlist

=

viewlist;

}

@Override

public

int

getCount()

{

//

设置成最大，使用户看不到边界

return

Integer.MAX_VALUE;

}

@Override

public

boolean

isViewFromObject(View

arg0,

Object

arg1)

{

return

arg0

==

arg1;

}

@Override

public

void

destroyItem(ViewGroup

container,

int

position,

Object

object)

{

//

Warning：不要在这里调用removeView

}

@Override

public

Object

instantiateItem(ViewGroup

container,

int

position)

{

//

对ViewPager页号求模取出View列表中要显示的项

position

%=

viewlist.size();

if

(position

<

0)

{

position

=

viewlist.size()

+

position;

}

ImageView

view

=

viewlist.get(position);

//

如果View已经在之前添加到了一个父组件，则必须先remove，否则会抛出IllegalStateException。

ViewParent

vp

=

view.getParent();

if

(vp

!=

null)

{

ViewGroup

parent

=

(ViewGroup)

vp;

parent.removeView(view);

}

container.addView(view);

//

此处可添加监听事件

return

view;

}

}

private

static

class

ImageHandler

extends

Handler

{

/**

*

请求更新显示的View。

*/

protected

static

final

int

MSG_UPDATE_IMAGE

=

1;

/**

*

请求暂停轮播。

*/

protected

static

final

int

MSG_KEEP_SILENT

=

2;

/**

*

请求恢复轮播。

*/

protected

static

final

int

MSG_BREAK_SILENT

=

3;

/**

*

记录最新的页号，当用户手动滑动时需要记录新页号，否则会使轮播的页面出错。

*

例如当前如果在第一页，本来准备播放的是第二页，而这时候用户滑动到了末页，

*

则应该播放的是第一页，如果继续按照原来的第二页播放，则逻辑上有问题。

*/

protected

static

final

int

MSG_PAGE_CHANGED

=

4;

//

轮播间隔时间

protected

static

final

long

MSG_DELAY

=

3000;

//

使用弱引用避免Handler泄露.这里的泛型参数可以不是Activity，也可以是Fragment等

private

WeakReference<NewsHomeFragment>

weakReference;

private

int

currentItem

=

0;

//

private

boolean

isOnce

=

true;

protected

ImageHandler(WeakReference<NewsHomeFragment>

wk)

{

weakReference

=

wk;

}

@Override

public

void

handleMessage(Message

msg)

{

super.handleMessage(msg);

final

NewsHomeFragment

fragment

=

weakReference.get();

if

(fragment

==

null)

{

//

Activity已经回收，无需再处理UI了

return;

}

//

第一次不删重复的消息

if

(currentItem

!=

0)

{

//

检查消息队列并移除未发送的消息，这主要是避免在复杂环境下消息出现重复等问题。

if

(fragment.mHandler.hasMessages(MSG_UPDATE_IMAGE))

{

fragment.mHandler.removeMessages(MSG_UPDATE_IMAGE);

}

}

switch

(msg.what)

{

case

MSG_UPDATE_IMAGE:

currentItem++;

fragment.mViewPager.setCurrentItem(currentItem);

//

准备下次播放

fragment.mHandler.sendEmptyMessageDelayed(MSG_UPDATE_IMAGE,

MSG_DELAY);

break;

case

MSG_KEEP_SILENT:

//

只要不发送消息就暂停了

break;

case

MSG_BREAK_SILENT:

fragment.mHandler.sendEmptyMessageDelayed(MSG_UPDATE_IMAGE,

MSG_DELAY);

break;

case

MSG_PAGE_CHANGED:

//

记录当前的页号，避免播放的时候页面显示不正确。

int

position

=

msg.arg1;

int

lastIndex

=

0;

int

index

=

position

%

fragment.mImageList.size();

for

(int

i

=

0;

i

<

fragment.mDotList.size();

i++)

{

fragment.mDotList.get(i).setBackgroundResource(R.drawable.dot_normal);

}

if

(fragment.mDotList.get(index)!=null)

{

fragment.mDotList.get(index).setBackgroundResource(R.drawable.dot_red);

}

lastIndex

=

index;

currentItem

=

position;

break;

default:

break;

}

}

}

}三、布局<LinearLayout

xmlns:android="/apk/res/android"

xmlns:tools="/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

tools:context=".MainActivity"

>

<RelativeLayout

android:layout_width="fill_parent"

android:layout_height="@dimen/news_pic_height"

>

<android.support.v4.view.ViewPager

android:id="@+id/view_pager"

android:layout_width="match_parent"

android:layout_height="@dim