在 Android 上使用 TextView 和 Html.ImageGetter 异步显示图像? [英] Display images on Android using TextView and Html.ImageGetter asynchronously?

问题描述

我想用 SpannableString 设置一个 TextView，它来自以下方法:

I want to set a TextView with SpannableString which is from the method below:

Html.fromHtml(String source, Html.ImageGetter imageGetter, 
   Html.TagHandler tagHandler)

但是这里的ImageGetter需要覆盖下面的方法:

But the ImageGetter here need to override the method below:

public abstract Drawable getDrawable(String source)

因为我需要从互联网上获取可绘制对象，所以我必须异步进行，似乎不是.

Because I need to get the drawable from the internet, I have to do it asynchronously and seems it is not.

如何让它发挥作用?谢谢.

How to make it work? Thanks.

推荐答案

现在我正在使用 AsyncTask 来下载 ImageGetter 中的图像:

Now I'm using an AsyncTask to download the images in the ImageGetter:

Spanned spannedContent = Html.fromHtml(htmlString, new ImageGetter() {

        @Override
        public Drawable getDrawable(String source) {
            new ImageDownloadAsyncTask().execute(textView, htmlString, source);
            return null;
        }
    }, null);

当图片下载完成后，再次将文本设置到 TextView 中.

And set the text again into the TextView when the image has been downloaded.

现在可以了.但是当我尝试执行 TextView.postInvalidate() 来重绘下载的图像时它失败了.我必须在 AsyncTask 中再次执行 setText().

Now it works. But It failed when I tried to do the TextView.postInvalidate() to redraw the downloaded images. I have to do setText() again in the AsyncTask.

有人知道为什么吗?

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