未根据本机脚本中 json api 的请求加载

Question

主-page.xml

<Page loaded="pageLoaded" class="page" xmlns="http://www.nativescript.org/tns.xsd"
 xmlns:lv="nativescript-ui-listview" 
xmlns:Card="nativescript-cardview">
<ActionBar title="Home" class="action-bar">
    </ActionBar>
    <lv:RadListView id="ls" items="{{ dataItems }}" row="0" loadOnDemandMode="Auto"
        loadMoreDataRequested="{{onLoadMoreItemsRequested}}">
        <lv:RadListView.itemTemplate>
 <Card:CardView class="card" elevation="40" radius="10" >
                <StackLayout class="card-layout" orientation="horizontal"  >
                    <StackLayout class="card-layout" orientation="vertical" >
                    <Label fontSize="20" text="{{ title }}" marginBottom="8" />
                 </StackLayout>
                </StackLayout>
            </Card:CardView>
        </lv:RadListView.itemTemplate>
    </lv:RadListView>
</Page>

主-page.js

var HomeViewModel = require("./main-view-model");
var homeViewModel = new HomeViewModel();
function pageLoaded(args) {
  var page = args.object;
   page.bindingContext = homeViewModel;
  listView = page.getViewById("ls");
  homeViewModel.initDataItems();
  homeViewModel.addMoreItemsFromSource(3);
  }
exports.pageLoaded = pageLoaded;

主视图-model.js

const httpModule = require("tns-core-modules/http");
var observableModule = require("tns-core-modules/data/observable");
var ObservableArray = require("tns-core-modules/data/observable-array").ObservableArray;
var posts = require("./posts.json");
var url1="https://en.wikipedia.org/w/api.php?action=query&format=json&titles=Janelle%20Mon%C3%A1e&prop=categories";
function HomeViewModel() {
  var viewModel = observableModule.fromObject({

    _sourceDataItems: [],

    initDataItems: function () {
       *//This function is for local json Its working as expected. 
      this._sourceDataItems = new ObservableArray();
      for (let i = 0; i < posts.names.length; i++) {

        this._sourceDataItems.push({ name: posts.names[i] });
      }//*
    httpModule.request({
        url: url1,
        method: "GET"
    }).then((response) => {
        for( var i=0; i<response.length;i++){
       this. _sourceDataItems.push({title: response.query.pages.categorymembers[i].title})
    }  

    }, (e) => {
    });

      },

    dataItems: [],
    addMoreItemsFromSource: function (chunkSize) {

      let newItems = this._sourceDataItems.splice(0, chunkSize);
      this.dataItems = this.dataItems.concat(newItems);
    },

    onLoadMoreItemsRequested: function (args) {
      console.log("---load item called----");
      const that = new WeakRef(this);
      const listView = args.object;
      if (this._sourceDataItems.length > 0) {
        setTimeout(function () {
          that.get().addMoreItemsFromSource(3);
          listView.notifyLoadOnDemandFinished();
        }, 4000);
        args.returnValue = true;
      } else {
        args.returnValue = false;
        listView.notifyLoadOnDemandFinished(false);
      }

    },
  });

  return viewModel;
}

module.exports = HomeViewModel;

在我的代码片段中，我无法从 json api 获取数据，而是从本地 json 获取数据。如果我把 json api 数据不显示，也不给出错误。请帮助我在加载更多数据请求时从 api 获取数据。 https://en.wikipedia.org/w/api.php?action=query&format=json&titles=Janelle%20Mon%C3%A1e&prop=categories，这是在编写使用 fetch() 的函数时用于演示，httpmodule.getjson() 它不适用于所有人让我知道我在哪里犯了错误。

Answer 1

正如我已经提到的，您没有正确解析数据。

这就是你的 JSON 的样子，

{
   ...
   "query":{
      "pages":{
         "13828397":{
            ...
            "categories":[
               {
                  "ns":14,
                  "title":"Category:1985 births"
               },
            ]
         }
      }
   }
}

所以你必须这样做，

var items = response.query.pages["13828397"].categories;
for( var i=0; i<items.length;i++){
   this._sourceDataItems.push({title: items[i].title})
}

未根据本机脚本中 json api 的请求加载

Not loading on request from the json api in nativescript

javascript

json

nativescript