从Url获取位图图像

Question

我想从URL获取位图图像：

Bitmap mage = getBitmapFromUrl(urlPhotoInFrameFirst);

public static Bitmap getBitmapFromUrl (String uri){
    URL url = null;
    try {
        url = new URL(uri);
        Bitmap image = BitmapFactory.decodeStream(url.openConnection().getInputStream());
        return image;
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

Bitmap image = BitmapFactory.decodeStream(url.openConnection().getInputStream());

Answer 1

如exception所述，您不能在主（UI）线程中进行网络调用。所以您需要将代码包装到runnable/thread中并调用它。可能是这样的：

public static class GetBitmapTask implements Runnable {

    private final String uri;
    private final Callback callback;

    public GetBitmapTask(String uri, Callback callback) {
        this.uri = uri;
        this.callback = callback;
    }

    @Override public void run() {
        try {
            URL url = new URL(uri);
            Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
            callback.onFinish(bmp);
        } catch (IOException e) {
            callback.onError(e);
        }
    }

    public interface Callback{
        void onFinish(Bitmap bitmap);
        void onError(Throwable t);
    }
}

用法：

new Thread(new GetBitmapTask("", new GetBitmapTask.Callback() {
    @Override public void onFinish(Bitmap bitmap) {
        //here is your bitmap
    }

    @Override public void onError(Throwable t) {
        //here you have to handle error
    }
})).start();

或者更好的方法：使用库加载图像。