Introducere in ASP.NET Controale Web Pagina in ... - Profs.info.uaic.ro
Introducere in ASP.NET Controale Web Pagina in ... - Profs.info.uaic.ro
Introducere in ASP.NET Controale Web Pagina in ... - Profs.info.uaic.ro
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<st<strong>ro</strong>ng>ASP</st<strong>ro</strong>ng>.<st<strong>ro</strong>ng>NET</st<strong>ro</strong>ng> 03.03.2014 9/30<br />
Care e mecanismul AutoPostback<br />
Cand AutoPostBack = true, <st<strong>ro</strong>ng>ASP</st<strong>ro</strong>ng>.<st<strong>ro</strong>ng>NET</st<strong>ro</strong>ng> foloseste un cod <st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> JavaScript pentru a realiza<br />
legatura d<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>tre client si server.<br />
Functia d<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> JavaScript se numeste __doPostBack() ce foloseste doua campuri ascunse pentru<br />
a transmite parametrii:<br />
<br />
<br />
Codul <st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> JavaScript (generat de <st<strong>ro</strong>ng>ASP</st<strong>ro</strong>ng>.<st<strong>ro</strong>ng>NET</st<strong>ro</strong>ng>) este urmatorul:<br />
<br />
<br />
<br />
<st<strong>ro</strong>ng>Cont<strong>ro</strong>ale</st<strong>ro</strong>ng>le ce au AutoPostBack = true vor apela metoda __doPostBack() folos<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>d<br />
atributele “onclick” sau “onchange”.<br />
Observatie<br />
In descrierea d<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> HTML, onclick si onchange apar ca atribute.<br />
Pe partea de cont<strong>ro</strong>l (<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> codul C# scris pentru pag<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>a) acestea sunt evenimente expuse de<br />
cont<strong>ro</strong>l.<br />
<br />
<br />
View State<br />
De fiecare data cand o pag<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>a este trimisa catre server, acesta recreaza obiectele d<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> pag<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>a<br />
porn<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>d de la def<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>itia acesteia, def<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>itie data <st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> fisierul .aspx.<br />
Eventualele modificari ale p<strong>ro</strong>prietatilor cont<strong>ro</strong>alelor sunt luate d<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>tr-un camp “ascuns” ce<br />
pastreaza ultima stare a pag<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>ii. Aceasta <st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>formatie constituie ceea ce numeste “view state”<br />
pentru pag<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>a. Informatiile sunt pastrate sub forma de perechi cheie/valoare.<br />
P<strong>ro</strong>prietatea <st<strong>ro</strong>ng>in</st<strong>ro</strong>ng> cauza este: EnableViewState = {true, false}.<br />
Observatie<br />
Chiar daca EnableViewState=false, sistemul cont<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>ua sa ment<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>a anumite <st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>formatii<br />
despre pag<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>a.<br />
Ioan Asim<st<strong>ro</strong>ng>in</st<strong>ro</strong>ng>oaei