java - when wouldn't i want to nullify every list item when using adapter? -


i'm using image adapter fill android listview.

i know adapter recycles items in listview.

but if need nullify every view in each item in list,

what's benefit anyway in recycling items?a

i mean, when wouldn't want nullify every list item?

i have tried nullify every view in item have thought - what's point in recycling anyway , how can avoid tedious nullifying.

adding:

my problem when change image view in first item's layout

i scroll down , see image has changed in 4th , 8th items.

it gives changed image instead of default one.

i can overcome putting defualt image everytime (appears in layout xml anyway)

but think: have on evry single view in item's layout?

why not defaults xml?

the listview recycles views contained in list. views merely visual representations of data provided adapter gives it. listview absolutely nothing actual data showing. don't have nullify anything.

the reason happens in listviews, list items same (usually). when list item goes out of sight, listview take view , give adapter. adapter fill view appropriate data , give listview. listview stick bottom (or top) of visible part of list. cuts down on overhead of inflating new views. limits memory usage of keeping view objects in memory. makes overall smoother scroll.


Comments

Post a Comment

Popular posts from this blog

apache - Remove .php and add trailing slash in url using htaccess not loading css -

i have add following code htaccess file removing .php extension , add trailing slash urls. worked fine reduced page loading speed , css code not loading @ all. pages ugly. please help rewriteengine on rewritebase / ## hide .php extension snippet # externally redirect /dir/foo.php /dir/foo rewritecond %{the_request} ^[a-z]{3,}\s([^.]+)\.php [nc] rewriterule ^ %1/ [r,l] # add trailing slash rewritecond %{request_filename} !-f rewritecond %{request_uri} !/$ rewriterule . %{request_uri}/ [l,r=301] # internally forward /dir/foo /dir/foo.php rewritecond %{request_filename} !-d rewritecond %{request_filename}.php -f rewriterule ^(.*?)/?$ $1.php [l] we can rewrite urls using .htaccess files. before writing in .htaccess files need verify kind of server using. can check server adding a <?php phpinfo(); ?> in php page. ensure mod_rewrite module enabled in apache server. can identified checking phpinfo included page. common methods used url rewriting follows ...
Read more

inno setup - TLabel or TNewStaticText - change .Font.Style on Focus like Cursor changes with .Cursor -

is possible change .font.style on focus tlabel or tnewstatictext happens cursor when use .cursor ? there no built-in support track mouse hovering in inno setup @ time. however, intercepting window procedure of controls can track yourself. following example need innocallback library: [setup] appname=my program appversion=1.5 defaultdirname={pf}\my program outputdir=userdocs:inno setup examples output [files] source: "innocallback.dll"; destdir: "{tmp}"; flags: dontcopy [code] #ifdef unicode #define aw "w" #else #define aw "a" #endif const gwl_wndproc = -4; wm_mousemove = $0200; type wparam = uint_ptr; lparam = longint; lresult = longint; twindowproc = function(hwnd: hwnd; umsg: uint; wparam: wparam; lparam: lparam): lresult; function setcapture(hwnd: hwnd): hwnd; external 'setcapture@user32.dll stdcall'; function releasecapture: bool; external 'releasecapture@user32.dll stdcall'; func...
Read more