RadListView更好的scrollToIndex（）行为

1 回答

• 0

  我刚用 scrollToIndex() 测试了给定的场景，但无法重现这种行为 . 所选行始终显示在屏幕顶部 . 您可以查看我的示例代码 .

  主page.xml

  <Page   loaded="onPageLoaded" xmlns:lv="nativescript-telerik-ui-pro/listview" xmlns="http://www.nativescript.org/tns.xsd">
      <lv:RadListView id="rdid" loaded="radlistviewlaoded" items="{{ dataItems }}" >
          <lv:RadListView.listViewLayout>
              <lv:ListViewLinearLayout scrollDirection="Vertical"/>
          </lv:RadListView.listViewLayout>
          <lv:RadListView.itemTemplate>
              <StackLayout orientation="vertical">
                  <Label fontSize="20" text="{{ itemName }}"/>
                  <Label fontSize="14" text="{{ itemDescription }}"/>
              </StackLayout>
          </lv:RadListView.itemTemplate>
      </lv:RadListView>
  </Page>
  

  主page.ts

  import { EventData } from "data/observable";
  import { Page } from "ui/page";
  import { HelloWorldModel } from "./main-view-model";
  import { ObservableArray } from "data/observable-array";
  import { RadListView } from "nativescript-telerik-ui-pro/listview";
  import {setTimeout} from "timer"
  
  // Event handler for Page "navigatingTo" event attached in main-page.xml
  export function onPageLoaded(args: EventData) {
      // Get the event sender
      var page = <Page>args.object;
      var listview:RadListView = <RadListView> page.getViewById("rdid");
      console.log("listview visibility "+listview.visibility);
      //listview.scrollToIndex(3);
      var array = new ObservableArray();
      for(var i=0;i<20;i++){
          array.push({itemName:"Name "+i, itemDescription:"desc "+i});
      }
      setTimeout(function(){
          listview.scrollToIndex(3)
      }, 2000)
  
      page.bindingContext = {dataItems:array};
  }
  
  export function radlistviewlaoded(args:EventData){
      console.log("RadListView loaded");
  }
  

  关于第二个问题，您可以使用 loaded 事件，以防您想知道何时在屏幕上加载了视图 . 如果您想知道RadListview是否可见，您可以使用visibility属性 .

  回复于 2024-05-06T02:49:28+08:00