Question

我正在尝试使用一组远程图像创建列表视图，并在加载它们时显示占位符图像。

var imageSource = require("image-source");
var imageCache = require("ui/image-cache");
var cache = new imageCache.Cache();
var defaultImageSource = imageSource.fromResource("img-loading”);

cache.enableDownload();
cache.placeholder = defaultImageSource;
cache.maxRequests = 5;

尝试使用fromFile而不是fromResource。

有什么难事吗？

Answer 1

我不确定您是如何使用pulbic class speech implements Recognizer{ startListening(){ //start the listener } @Override onResult(){ //hear i get my string after a random various amount of time //(when the recognizer is done with hearing my stuff) //at this point i want to let the other class know, that im done here } }但是无法直接将ImageCache对象设置为ImageCache的来源。为了达到你想要的效果，你必须使用这样的东西（取自http://pstaev.blogspot.com/2016/04/using-nativescripts-imagecache-to-cache.html）：

主page.xml

Image

主page.ts

<Page xmlns="http://schemas.nativescript.org/tns.xsd" 
      navigatingTo="navigatingTo">
    <ListView items="{{ images }}">
      <ListView.itemTemplate>
        <GridLayout>
          <Image src="{{ imageSrc }}" stretch="aspectFill" height="100"/>
        </GridLayout>
      </ListView.itemTemplate>
    </ListView>
</Page>

图像item.ts

import observableArray = require("data/observable-array");
import observable = require("data/observable");
import imageItem = require("./image-item");
import pages = require("ui/page");

export function navigatingTo(args: pages.NavigatedData)
{
    var page = <pages.Page>args.object;
    var model = new observable.Observable();
    var images = new observableArray.ObservableArray<imageItem.ImageItem>();

    images.push(new imageItem.ImageItem("http://foo.com/bar1.jpg"));
    images.push(new imageItem.ImageItem("http://foo.com/bar2.jpg"));
    // ...
    images.push(new imageItem.ImageItem("http://foo.com/bar100.jpg"));

    model.set("images", images);
    page.bindingContext = model;
}

Nativescript - 如何从ui / image-cache正确使用占位符属性使其工作？

1 个答案: