Dambudziko guru rine chekuita nekushandisa iyo ngFor dhairekitori ine index nderekuti inogona kutungamira kune isingatarisirwe mhedzisiro kana iyo data ichidzokororwa pamusoro pekuchinja. Izvi zvinodaro nekuti index yacho haingogadziriswe otomatiki kana zvinhu zvawedzerwa kana kubviswa kubva muhurongwa, saka kana chinhu chitsva chikaiswa pa index 0, zvimwe zvinhu zvese zvinenge zvadzikiswa neimwe. Izvi zvinogona kutungamira kune isiriyo data inoratidzwa mumaonero ako kana maitiro asingatarisirwe mukushandisa kwako.
<ul>
<li *ngFor="let item of items; let i = index">{{i}} - {{item}}</li>
</ul>
1. Uyu mutsara wekodhi unogadzira rondedzero isina kurongeka.
2. Iyo *ngFor dhairekitori inoshandiswa kutenderera nezvinhu zvakarongwa uye kuratidza chinhu chimwe nechimwe chiri murondedzero.
3. Izwi rekuti rega rinoshandiswa kuzivisa shanduko inonzi "chinhu" iyo inobata chinhu chazvino mukudzokororwa kwe loop.
4. Izwi rekuti rega rinoshandiswa zvakare kuzivisa shanduko inonzi "i" iyo inobata index yechinhu chazvino mukudzokorora kwe loop.
5. Mutsara uyu unoratidza chinhu chimwe nechimwe chiri murunyoro nenhamba yayo ye index (kubva pa0).
Chii chinonzi Angular
Angular iJavaScript-based open-source front-end web application framework inonyanya kuchengetedzwa neGoogle uye nenharaunda yevanhu nemakambani kugadzirisa matambudziko mazhinji anowanikwa mukugadzira maapplication epeji rimwe chete. Izvo zvikamu zveJavaScript zvinoenderana neApache Cordova, chimiro chinoshandiswa kugadzira muchinjika-chikuva nharembozha. Inovavarira kurerutsa budiriro uye kuyedzwa kwezvishandiso zvakadaro nekupa chimiro chemutengi-parutivi modhi-view-controller (MVC) uye modhi-view-viewmodel (MVVM) zvivakwa, pamwe chete nezvinhu zvinowanzoshandiswa muhupfumi hweInternet application.
ngFor element
NgFor ndeye Angular structural dhairekitori iyo inotibvumira kutenderera kuburikidza nedata uye kugadzira template yechinhu chimwe nechimwe muhurongwa kana chinhu. Inoshandiswa kudzokorora yakapihwa HTML element nhamba yakatarwa yenguva. NgFor inogona kushandiswa kuratidza data kubva kune yakarongwa, chinhu, kana tambo. Inogonawo kushandiswa kugadzira HTML zvinhu zvichibva pane zvakakoshera zvearray kana chinhu. NgFor inowanzo shandiswa pamwe chete nemamwe mirairo yeAngular senge ngIf uye ngSwitch.
Nzira yekuwana sei index ye ngFor element
Unogona kushandisa index keyword kuti uwane index yechinhu mune ngFor loop. Syntax yeizvi ndeiyi inotevera:
Mumuenzaniso uyu, iyo "i" shanduko ichange iine indekisi yazvino ye loop. Iwe unogona ipapo kushandisa shanduko iyi kuwana kana kugadzirisa zvinhu mune yako runyorwa.
