Implementation of circular advertising space using viewpager in Android

How to realize circular playback

Now the loop playback on the Internet is realized by returning a large value in the getcount () method of the adapter, and the instantiateitem (ViewGroup container, int position) makes the viewpager play continuously by taking the remainder (position / data. Size()).

Here we implement it by modifying the data source and setting the currentitem.

Modify data source:

Setting currentitem needs to be done in onpagechangelistener object:

The adapter is the same as the general viewpager adapter.

How to realize automatic circulation:

There are many methods to realize automatic loop, such as timer, handler, alarm, etc. Here we use handle

The custom handler class is as follows:

After obtaining the data and setting the adapter for the viewpager, you can start the automatic loop:

Here we use weak references, mainly to prevent memory overflow.

be careful:

When setting currentitem, be sure to set it in onpagechangelistener. A white screen will appear when setting it in finishupdate (view) of the adapter. If any God knows, please give me advice.