java - 如何从url获取图像并将其存储在Bitmap变量中

Question

我是 Android 新手。我想从 url 获取图像并将其设置为 Bitmap 变量。我尝试了很多代码但没有得到。

这是我的代码:

String url = "https://www.google.com/intl/en_ALL/images/logo.gif";
ImageDownloaderTask image = new ImageDownloaderTask();
image.execute(new String[]{url});
Bitmap bitmap = image.bImage;

ImageDownloaderTask.java

public class ImageDownloaderTask extends AsyncTask<String, Void, Bitmap> {

Bitmap bImage;

@Override
public Bitmap doInBackground(String... params) {
    return downloadBitmap(params[0]);
}

private Bitmap downloadBitmap(String src) {
   HttpURLConnection urlConnection = null;
    try {
        URL url = new URL(src);
        urlConnection = (HttpURLConnection) url.openConnection();

        int statusCode = urlConnection.getResponseCode();
        if (statusCode != HttpStatus.SC_OK) {
            return null;
        }

        InputStream inputStream = urlConnection.getInputStream();
        if (inputStream != null) {

            Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
            return bitmap;
        }
    } catch (Exception e) {
        Log.d("URLCONNECTIONERROR", e.toString());
        if (urlConnection != null) {
            urlConnection.disconnect();
        }
        Log.w("ImageDownloader", "Error downloading image from " + src);
    } finally {
        if (urlConnection != null) {
            urlConnection.disconnect();

        }
    }
    return null;
}

protected void onPostExecute(Bitmap result) {
      bImage = result;
}
}

提前致谢...

Answer 1

这是您可以使用的代码

new DownloadImage().execute("https://www.google.com/intl/en_ALL/images/logo.gif");



// DownloadImage AsyncTask
private class DownloadImage extends AsyncTask<String, Void, Bitmap> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        // Create a progressdialog

    }

    @Override
    protected Bitmap doInBackground(String... URL) {

        String imageURL = URL[0];

        Bitmap bitmap = null;
        try {
            // Download Image from URL
            InputStream input = new java.net.URL(imageURL).openStream();
            // Decode Bitmap
            bitmap = BitmapFactory.decodeStream(input);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }

    @Override
    protected void onPostExecute(Bitmap result) {
        // Do whatever you want to do with the bitmap

    }
}