android - 使用 URL 用屏幕宽度的图像填充 TextView

Question

我正在从 URL 加载提要并获取包含我放入 TextView 中的图像的文本，但是 TextView 中的图像在超过 3.5 英寸的显示器上很小.我猜问题出在 setBounds 方法中。这是我的类(class):

public class URLImageParser implements Html.ImageGetter {
Context c;
TextView container;


/***
 * Construct the URLImageParser which will execute AsyncTask and refresh the container
 * @param t
 * @param c
 */



public URLImageParser(TextView t, Context c) {
    this.c = c;
    this.container = t;
}

public Drawable getDrawable(String source) {
    URLDrawable urlDrawable = new URLDrawable();

    // get the actual source
    ImageGetterAsyncTask asyncTask =
            new ImageGetterAsyncTask( urlDrawable);

    asyncTask.execute(source);

    // return reference to URLDrawable where I will change with actual image from
    // the src tag
    return urlDrawable;
}

public class ImageGetterAsyncTask extends AsyncTask<String, Void, Drawable> {
    URLDrawable urlDrawable;

    public ImageGetterAsyncTask(URLDrawable d) {
        this.urlDrawable = d;
    }

    @Override
    protected Drawable doInBackground(String... params) {
        String source = params[0];
        return fetchDrawable(source);
    }

    @Override
    protected void onPostExecute(Drawable result) {
        try {
            // set the correct bound according to the result from HTTP call
            urlDrawable.setBounds(0, 0, result.getIntrinsicWidth(), result.getIntrinsicHeight());


            // change the reference of the current drawable to the result
            // from the HTTP call
            urlDrawable.drawable = result;


            // For ICS
            URLImageParser.this.container.setHeight((URLImageParser.this.container.getHeight()
                    + result.getIntrinsicHeight()));

            // redraw the image by invalidating the container
            URLImageParser.this.container.invalidate();
        } catch (NullPointerException ex){
            urlDrawable.setBounds(0,0,0,0);
            urlDrawable.drawable = result;

        }
        // Pre ICS
        URLImageParser.this.container.setEllipsize(null);
    }

    /***
     * Get the Drawable from URL
     * @param urlString
     * @return
     */
    public Drawable fetchDrawable(String urlString) {
        try {
            InputStream is = fetch(urlString);
            Drawable drawable = Drawable.createFromStream(is, "src");
            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
            return drawable;
        } catch (Exception e) {
            return null;
        }
    }

    private InputStream fetch(String urlString) throws MalformedURLException, IOException {
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet request = new HttpGet(urlString);
        HttpResponse response = httpClient.execute(request);
        return response.getEntity().getContent();
    }
  }
}

我该如何解决我的问题？我想用图像填充 TextView 使用设备屏幕宽度或任何其他可以制作大尺寸图片的宽度。

Answer 1

如其他地方所述，您不能使用内在度量来扩展。您需要考虑屏幕像素和密度。换句话说，当图像不在自动缩放的对象中时，您需要计算图像的宽度。

这是一个很好的引用:

Android: How to stretch an image to the screen width while maintaining aspect ratio?

此外，您应该考虑使用“sp”而不是“dp”，因为您的图像是与文本对齐显示的。读这个:

What is the difference between "px", "dp", "dip" and "sp" on Android?

换句话说，您的图像可能应该随文本以及屏幕尺寸和屏幕密度缩放。