动态设置线性布局背景

Question

我想以下列方式动态设置线性布局背景:

1. 通过XML解析从Web URL获取图像,然后将该图像存储到SD卡中.

2. 现在图像保存到SD卡中.

3. 将该图像设置为应用程序中的线性布局背景.

现在我陷入了第三步.有人可以帮忙吗？

Answer 1

用这个:

Bitmap bmImg = BitmapFactory.decodeStream(is);
BitmapDrawable background = new BitmapDrawable(bmImg);
linearLayout.setBackgroundDrawable(background);

还要检查一下:如何在Android中将Bitmap转换为Drawable？

Answer 2

我已经这样做了：

private RelativeLayout relativeLayout;

在创建：

relativeLayout= (RelativeLayout)findViewById(R.id.relativeLayout);

new LoadBackground("http://www.tmonews.com/wp-content/uploads/2012/10/androidfigure.jpg",
            "androidfigure").execute();

的AsyncTask到负载在图像背景：

private class LoadBackground extends AsyncTask<String, Void, Drawable> {

    private String imageUrl , imageName;

    public LoadBackground(String url, String file_name) {
        this.imageUrl = url;
        this.imageName = file_name;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected Drawable doInBackground(String... urls) {

        try {
            InputStream is = (InputStream) this.fetch(this.imageUrl);
            Drawable d = Drawable.createFromStream(is, this.imageName);
            return d;
        } catch (MalformedURLException e) {
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }
    private Object fetch(String address) throws MalformedURLException,IOException {
        URL url = new URL(address);
        Object content = url.getContent();
        return content;
    }

    @Override
    protected void onPostExecute(Drawable result) {
        super.onPostExecute(result);
        relativeLayout.setBackgroundDrawable(result);
    }
}

希望这会帮助你。