Txheej txheem cej luam: Nyob rau cov tshooj no peb yuav tham txog ntau lub ntsiab lus refreshing rua kev. Rau cov refreshing yog ib tug nam tseem ceeb hauv cov ntawv web. Li ntawd, tus tsim tawm lub web no yuavtsum tau muaj ib tug to taub zoo txog kev sib txawv le caag thiab lawv zoo/disadvantages. Qhov tsab xov xwm no yuav nrog koj sib tham tswv yim txog tej teeb meem thiab cov ntsiab ntawm cov khoom noj khoom haus web cheeb tsam. Qhov no yog paub ntau ncha lug ua dynamic web cov cim kom nco ntsoov rau cov neeg siv tau cov ntaub ntawv tam sim no.
Taw qhia: Lub ntsiab lus rau phab web refreshing yuav tsum zoo rau txhua daim ntaub ntawv web niaj hnub. Qhov no feem ntau ntau muaj qhov twg cov ntsiab lus muaj ib feem tseem ceeb thiab plays lub luag hauj lwm loj. Tos qab nws yog pab cov neeg uas muaj ntaub ntawv kawm tam sim no thiab kho tshiab. Developers siv txawv mechanisms kom muaj kev kawm dynamic. Cov kev cai uas ib txwm refreshing qhov web page tag nrho. Tiam sis nws muaj ib co tej yam tsis zoo rau neeg siv los lawm thiab usability sab. Tab sis peb yuav tsum to taub tias qhov kev siv ntawm ib tug txheej txheem yuav tsum nyob li qhov yuav tsum tau ua hauv daim ntawv thov web. Yog hais tias tus tag nrho sab refresh tsis hamper lub functionality ces nws yuav ib tug followed. Yog hais tias koj yuav tsum tau refreshing ib tug nqe ces peb yuav tsum npaj kom haum.
Txoj kev cai ntawm refreshing lub ntsiab lus: Ua ntej peb sib tham txog tus siab heev thiab nws txoj kev los kho kom tshiab ntawv/phab Web site, peb yuav tsum to taub txog cov kev uas twb muaj lawm thiab lawv pros/cons. Txoj kev cai, feem ntau ntawm nplooj tag nrho refreshed siv mechanisms sib txawv. Nram qab no yog tej qho kev ua tshiab phab ntawv nrov. Tab sis cov mechanisms kuj muaj teeb meem thiab peb yuav sib tham txog nws rau hauv seem tom ntej no.
- Qhia tau meej heev los txhaj rau ib lub pob los yog txuas mus xa thov
- Yog txhaj F5/refresh khawm los reload lub webpage tag nrho
- Uas yog ib co ntawv lossis/meta uas refreshes cov nplooj ntawv tom qab paj yuav luv
- Thaum uas siv cov java tsab ntawv tso cai rau reload phab raws ib timer
- Thaum uas siv cov jquery tso cai rau ua tshiab rau sab hauv muaj ib tug yuav luv
- Thaum xa tawm ib daim ntawv kom muab cov ntaub ntawv tshiab uas los kuj ib yam txheej refresh
Lub disadvantages lub ntsiab ntawm cov le caag tag nrho yog tias cov txheej refresh yog nyob sab. Nws txhais tau tias cov ntaub ntawv nqi yog ib txwm ua based rau ntawm tag nrho txawm hais tias nws tseem tsis tau txhua lub sijhawm. Li ntawd, yog hais tias koj yuav tau ua cov tshiab ib qho seem ntawm cov ntaub ntawv phab ces koj tau ua tshiab rau tag nrho sab. Cov nyhuv cuab kev cov kauj yog ua laim laim rau sab thiab plam koj concentration los ntawm ib tug seem. Qhov no yog annoying tiag tiag los ntawm tus foundations thiab li tau muaj tej yam tsis zoo rau sab usability. Yog tias ntawm muaj ntau lub ntsiab lus thiab koj yuav nyob nruab nrab ntawm nws, ces cia li refresh yuav siv sij hawm koj rov qab mus saum nws thiab koj poob koj phau ntawv kos. Qhov no yog poob cov ntaub ntawv nyob rau hauv ib daim ntawv uas yog hauv ntawm koomhaum twb. Yog rau sab refreshes ces koj poob koj nkag teb chaws thiab tau rov sau nws dua. Li ntawd, peb yuav nco ntsoov cia cov disadvantages hauv qab no.
- Loosing scroll txoj hauj lwm vim sab tas nrho refresh
- Loosing twb sau ntaub ntawv
- Laim laim ntawm cov nplooj ntawv thaum cov nqi uas tshab
- Cov neeg tsis pom kev
Nyob rau hauv lub Web site niaj hnub txoj kev siv, tag nrho qhov web page muaj nqaij ntau khej coj txawv functionalities. Piv txwv, tej zaum tej feem puas uas qhia lag luam Tshuag hloov tshiab tam sim no, ib daim ntawv kom muab ib co tswv yim ntawv cov neeg siv yog ib co uas qhia tam sim no tus xov xwm thiab tej seem. Vim li ntawd yog cov yuav tsum tau qhia tau ib yam txawv los ntawm lwm tus sab. Peb yuav tsum to taub li cas seem no yuav tsum tau ib qho hloov tshiab thiab tshua uas zoo li qub. Tab sis, yog hais tias peb ib txwm coj tas nrho phab refresh kev ces nws yog tsis muab rau neeg lub hom phiaj ntawm tus ntawv xwb. Ces tus refresh qha kev lawm yeej yuav sib txawv ntawm tsab ntawv teev npe foundations.
Niaj hnub nimno ntawm qhov Web site refresh le caag:
Thawj zaug mus kom ze: Yuav pib muaj kev xaiv yooj yim, peb yuav tau muab siv ntas. Tab sis, nyob hauv tej num, raws li cov webpage nrho faib ua khej cais nws muaj tsis zoo yeej quas. Yog li ntawd, saib cov nplooj ntawv phem. Thiab txoj kev xaiv refresh yog tsis lig solved siv ntas vim nws tsuas solves tej yam pom tau qhov sib.
Mus kom ze thib ob: Ob thiab feem ntau tej zaum ib ntawm cov kev xaiv uas zoo yog siv applet thiab DHTML. Thaum uas siv cov applet uas koj yuav thauj tej seem ntawm cov ntaub ntawv hauv web page tsis puas tabkaum lwm sab lus thiab tus DHTML yuav pab kom koj qhia hais tias cov ntu html thiab qhia txoj kev. Kauj yog heev npaum thiab muab txoj kev ywj pheej txav hnub tim khawv khuav web browser thiab neeg rau zaub mov. Thiab tseem ceeb tshaj, nws tsis yog nyob ntawm seb yog thaum cov mus thiab NCEJ haujlwm nyob phab. Tam sim no yog peb xav txog sab tod los ntawm applet, ces yog ib qhov teeb meem ruaj ntseg thaum uas tab tom siv nyob rau hauv cov nplooj ntawv Web site. Applet sau nyob hauv tus browser JVM kom tus neeg siv yuav tsum tau ntsia mus rau applet JVM ua hauj lwm kom zoo. Thiaj li yog tus neeg tsis muaj twg paub txog txoj kev quav dej caws (zoo li JVM no) ces nws yuav pom tias nws nyuaj rau siv.
Peb mus kom ze: Tam sim no peb yuav tham txog txoj kev thib peb uas yog siv tau HTTP thiab NCEJ yog ib txoj kev sib txawv. Kev xaiv no yuav raug siv los ntawm java tsab ntawv developers thiab laij tau qhov tas nrho phab refresh no. Ntawm no mus kom ze, java tsab ntawv xa mus thov kom cov neeg rau zaub mov thiab tau txais nws cov lus teb. Tiam sis qhov txawv, nws tsis muaj yam ntxim rau lwm seem ntawm lub sab. Tus neeg siv yuav siv tej timer los yog ib co ntawv kom ua tau rau tus java tsab ntawv thiab cov nuj nqi java tsab ntawv xa mus thov kom haum. Tom qab koj tau txais cov ntaub ntawv tsim tawm siv tau as per lub. Cov DHTML pab sab lus thiab tso saib cov ntaub ntawv uas tau txais los ntawm tsab ntawv java.
Peb muab ib tug piv txwv yuav to taub
Qhia 1: Tus qauv chaws qhia kev siv ntawm HTTP thov mus nqa cov ntaub ntawv
[chaws]
<html>
<tsab ntawv>
Var xmlDocRefRef = thov ;
getData muaj nuj nqi() {
Yog hais tias (typeof qhov rai. ActiveXObject != ' undefined’ ) {
xmlDocRef = ActiveXObject tshiab(“Microsoft.XMLHTTP”);
xmlDocRef.onreadystatechange = processData ;
}
ntxiv {
xmlDocRef = XMLHttpRequest tshiab();
xmlDocRef.onload = processData ;
}
xmlDocRef.open( “TAU”, “content_refresh.html”, tseeb );
xmlDocRef.send( thov );
}
processData muaj nuj nqi() {
Yog hais tias ( xmlDocRef.readyState != 4 ) rov qab mus ;
document.getElementById(“outputdata”).tus nqi = xmlDocRef.responseText ;
}
emptyData muaj nuj nqi() {
document.getElementById(“outputdata”).tus nqi = ' Data ntxuav, Xovxwm GetData mus nqa cov ntaub ntawv’ ;
}
</tsab ntawv>
<lub cev>
<textarea npav =”outputdata” cols ='50’ natwm = '20'>Tsis muaj ntaub ntawv retrieved. Xovxwm ' GetData’ mus nqa cov ntaub ntawv </textarea>
<br></br>
<khawm onclick =”getData()”>GetData</khawm>
<khawm onclick =”emptyData()”>CleanData</khawm>
</lub cev>
</html>
[/chaws]
Yog tus ntawm yuav tau loaded li nram qab no
Pic 1: Cov html phab loaded
Tam sim no koj nyem rau ntawm qhov 'GetData' khawm thiab cov ntaub ntawv yuav tau fetched thiab tso tawm kom pom li nram qab no.
Pic 2: Cov ntaub ntawv loaded ntse
Ib kis peb yuav tsum to taub yog tias txoj kev yuav ua mus txog npav. Nws txhais tias qhov browser no yuav tsum tau xa tej kev thov kom muab cov ntaub ntawv thiab ces nws yuav tau retrieved thiab tso tawm kom pom. Tab sis thaum applet txoj kev yuav tau caw kaw lus thiab tus neeg rau zaub mov yuav thawb cov ntaub ntawv mus rau applet thaum twg yuav tsum tau. Tab sis thaum HTTPRequest tsis, neeg tsuas muab tau cov ntaub ntawv raws li qhov kev thov. Li ntawd, polling yog ib yam tseem ceeb tau mus muab suav cov hom le caag. Li ntawd, lub caij nyoog kev nyob li qhov yuav tsum tau ua hauv daim ntawv thov thiab yuav tsis muaj ib qho kev uas yuav ntsuas hauv txhua scenarios.
Xaus: Mam tam sim no peb muaj sab laj ntau le caag rau phab refreshing. Nws yuav ua rau cov neeg siv ntau mus saib, kho kom raug thiab xa cov ntaub ntawv rau webpage tsis muaj kev kawm txawj annoying ib txhij. Tus lwm kom zoo dua yog tias tus neeg siv yuav saib lawv hloov tshiab tam sim ntawd tsis muaj refreshing rau sab tag nrho. Yog lwm tus tej yam, nws tshem tawm cov laim laim, yuav los txhawb kom scroll, tsis hais txog cov ntaub ntawv unsaved. Vam tias koj yuav sim kom paub cov kev xaiv thiab nrhiav tau nyob rau hauv koj lub web daim ntawv thov kev pab tau.
