android - 如何在 Android 中从 web url 设置图像按钮资源？

Question

我有一个图像按钮，想从互联网 URL 设置背景图像。我不想将背景图片保存到 SD 卡中，而是我的图像按钮的图像需要是 URL。我怎么能在Android中做到这一点

Answer 1

从未尝试过，但希望这对你有用

private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
    try {
        InputStream is = (InputStream) this.fetch(url);
        Drawable d = Drawable.createFromStream(is, saveFilename);
        return d;
    } catch (MalformedURLException e) {
        e.printStackTrace();
        return null;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}

和图像视图

ImageView IV= (ImageView)findViewById(R.id.imageId);      
Drawable drw = ImageOperations(this,url,filename)
IV.setBackgroundDrawable(drw)

获取网址

    public Object fetch(String address) throws MalformedURLException,IOException {

    URL url = new URL(address);
    Object content = url.getContent();
    return content;
}

Answer 2

尝试这个

        Bitmap bitmap;
class loadImage extends AsyncTask<Void , Void, Void>{
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }
    @Override
    protected Void doInBackground(Void... params) {
        URL url = new URL(stringURL);
        URI uri = new URI(url.getProtocol(), url.getHost(),
                url.getPath(), url.getQuery(), null);
        HttpURLConnection connection = (HttpURLConnection) uri
                .toURL().openConnection();
        connection.setDoInput(true);
        connection.connect();
        InputStream input = connection.getInputStream();
        ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();

        int bufferSize = 1024;
        byte[] buffer = new byte[bufferSize];
        int len = 0;
        while ((len = input.read(buffer)) != -1) {
            byteBuffer.write(buffer, 0, len);
        }
        byte[] img = byteBuffer.toByteArray();
        byteBuffer.flush();
        byteBuffer.close();
        input.close();
        bitmap = BitmapFactory.decodeByteArray(img, 0, img.length);
        return null;
    }
    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        ImageButton image_btn = (ImageButton)findViewById(R.id.your_image_button_id);
        image_btn.setImageBitmap(bitmap);
    }
}

Answer 3

首先，您必须将图像下载为 Drawable： Android Drawable Images from URL

然后将其设置为背景可绘制

button.setBackgroundDrawable(drawable)