Thanks Victor, for your answer, but the adapter alone doesn't solve my problem. The softreference is cleared, by definition, when the system needs memory, not when then objects looses all the references.
Thanks to Streets of Boston too, I haven't thounght about your solution with LinkedHashMap, overriding "removeEldestEntry()" to limit the cache-size. It' very interesting as solution. I'm going to try quickly. I will inform you about the result. Thanks to all. On 17 Nov, 20:37, Streets Of Boston <flyingdutc...@gmail.com> wrote: > Use a LinkedHashmap for a cache and implement the method > 'removeEldestEntry(...)' appropriately to limit the cache-size. > > If the LinkedHashmap cache contains your image, code the > 'getView(...)' of your list-adapter to immediately assign the > (thumbnail) image to the image-view. > > If the LinkedHashmap cache does not contain your image, code the > 'getView(...)' to assign a temporary 'loading...' placeholder to the > image-view and start (asynchronously) loading the missing thumbnail. > When the thumbnail is loaded, add it to the cache. When the cache > changes and/or the list stops scrolling (see List13.java from the > APIDemos as an example), replace any temporary 'loading...' > placeholder with the newly loaded image(s). > > On Nov 17, 8:50 am, Paolo <brand...@gmail.com> wrote: > > > > > Hi there! > > I have to manage several Bitmap in a ListView where each row is > > composed by one thumbnail and one textview. > > This ListView can be very long, over 500 rows... > > > There are two problems I have to solve: > > > 1) it is better if I cache all the bitmaps, maybe using SoftReferences > > in a HashMap. I've tried this way, but I noticed a strange behavior > > with the SoftReferences. It seems that the GC clean them too fast. > > Why? > > > 2) In order to implement the cache correctly I'd also like to > > understand which is the best practice you suggest me to realize a > > "image lazy loading". For example... I'm thinking to load all the data > > for first and then to load only the thumbnails, but only those really > > visible on the device screen at the and of the scroll action. > > > Thanks in advance. > > > Paolo -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
