每次调用OnCreate时运行线程

Question

我尝试在每次创建活动时运行以下线程。它第一次工作，但如果我按下后退按钮并尝试再次导航到活动，它总是崩溃第二次。我怎样才能确保这个线程每次都运行成功呢？

new Thread(new Runnable() {

                public void run() {

                    for (int i = 0; i < 5; i++) {

                        try {
                            URL url = new URL(priceRangeLargeImageString[i]);
                            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                            connection.setDoInput(true);
                            connection.connect();
                            InputStream input = connection.getInputStream();
                            Bitmap bitmap = BitmapFactory.decodeStream(input);
                            largeImage.add(bitmap);

                        } catch (IOException e) {
                            e.printStackTrace();
                            Log.e("Exception", e.getLocalizedMessage());
                        }
                    }
                    latch.countDown();
                }
            }).start();

                try {
                    latch.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                addtoView();

    if (convertView == null) {
        convertView = inflater.inflate(R.layout.forlist, parent, false);

    }

  //  parent.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);

    TextView address = (TextView) convertView.findViewById(R.id.Address);
    address.setText(flowername.get(position));

    TextView price = (TextView) convertView.findViewById(R.id.price);

    price.setText("$" + flowerprice.get(position), TextView.BufferType.SPANNABLE);
    Spannable spannable = (Spannable) price.getText();
    spannable.setSpan(STRIKE_THROUGH_SPAN, 0, price.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

    TextView discount = (TextView) convertView.findViewById(R.id.discountPrice);

   discountedPrice = Double.parseDouble(flowerprice.get(position)) / 1.15;
   String priceString = new DecimalFormat("$##.00").format(discountedPrice);
    discount.setText(priceString);

    TextView size = (TextView) convertView.findViewById(R.id.sizes);
    size.setText(flowersize.get(position));

    final ImageView image = (ImageView) convertView.findViewById(R.id.flowerImage);
    image.setImageBitmap(flowerimage.get(position));

    return convertView;
}

Answer 1

如果导航回已创建的活动，则不会调用onCreate。

尝试将代码移动到onResume（）中：

@Override
protected void onResume(){
    super.onResume();
new Thread(new Runnable() {

            public void run() {

                for (int i = 0; i < 5; i++) {

                    try {
                        URL url = new URL(priceRangeLargeImageString[i]);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.setDoInput(true);
                        connection.connect();
                        InputStream input = connection.getInputStream();
                        Bitmap bitmap = BitmapFactory.decodeStream(input);
                        largeImage.add(bitmap);

                    } catch (IOException e) {
                        e.printStackTrace();
                        Log.e("Exception", e.getLocalizedMessage());
                    }
                }
                latch.countDown();
            }
        }).start();
}