How to use Selector when click a item in list

I occur a problem when develop a application on android.

There have two image which can be download from server in a list item, it will show one image and will show another image when user select or click this item . if I try to download another image from server when user click it,the user will never have time to see it, for this time is shorter than download image fo开发者_如何学Crm server, so i want to download two of them,and when I click it again,the app can invoke another image from local.

but I do not know how to invoke this image ?

Any suggestion will be appreciate.

thx

put selector images on the drawable resource folder. if you download it from server then it will reduce your apps performance. check this answer of mine.