The possible problems of ListView and its optimization

Occurrence: In Fragmentactivity, two adjacent fragment have a large number of data requests

1, guess the reason: the memory is really too small

Result: There is still an error after changing the memory of the big mobile phone

2, the need to show the data are reduced, but the amount of data requested is still very large

Result: This error still occurs

3. See links http://blog.csdn.net/lizhenmingdirk/article/details/30490789

Without the use of a background image, using a solid color, there will be no practical results: the same mistakes will still be reported

Result: This error still occurs

Two, ListView of cotton after investigation has three kinds of programs
1, asynchronous load picture (dual cache: Internal cache and SD card cache)
2, request 10 each time, require the user to continue to request the next 10 http://download.csdn.net/download/anyifeng5257/4841040
3. Add the picture in the GetView to the stack, start the asynchronous thread to load the picture from the top of the stack, and make sure the picture of the current display area is displayed first.
Adjust the load thread priority to thread.norm_priority-1 and do not clock slices with UI threads to make scrolling smoother. Source: Http://download.csdn.net/detail/dolaameng328/5054440#comment

Note that you must add the SD card to read and write permissions online This lazylist really can be used, but the transplant to my own application when there is a problem
Bitmapfactory Explicit Termination method "Close" not called
Mainly because the Infilestream is not closed. Correction scheme: HTTP://ASK.CSDN.NET/QUESTIONS/53

Bitmapfactory.options O2 = new Bitmapfactory.options ();
        O2.insamplesize = scale;
        FIS = new FileInputStream (f);
        b = Bitmapfactory.decodestream (FIS, NULL, O2);
        Fis.close ();

return b;
Solution Resolution: Use picture caching, cache the URL image, then read the cache
Note that you must add read and write access to the SD card

1, Filecache documents

The Getcachedir () method is used to get the/data/data//cache directory

The Getfilesdir () method is used to get the/data/data//files directory

Reference: http://www.cnblogs.com/liulipeng/archive/2013/02/22/2922733.html

http://blog.csdn.net/yuzhiboyi/article/details/8645730 2, SoftReference soft reference reason: http://www.linuxidc.com/Linux/ 2011-09/42288.htm
Principle: http://blog.csdn.net/kavendb/article/details/5935577