Question

我每次创建活动时都试图运行以下线程。它是第一次工作，但如果我按下后退按钮并尝试再次导航到该活动，它总是第二次崩溃。如何确保每次都成功运行此线程？

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();

我的线程正在填充我在这里放入自定义适配器的ArrayList：

public View getView（int position，View convertView，ViewGroup parent）{

    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;
}

我的logcat如下：

03-09 21：33：01.540 18890-18890 / com.example.andrewberkowitz.bae W / dalvikvm：threadid = 1：线程退出未捕获的异常（group = 0x41862da0） 03-09 21：33：01.550 18890-18890 / com.example.andrewberkowitz.bae E / AndroidRuntime：FATAL EXCEPTION：main 过程：com.example.andrewberkowitz.bae，PID：18890 java.lang.IndexOutOfBoundsException：索引0无效，大小为0 at java.util.ArrayList.throwIndexOutOfBoundsException（ArrayList.java:255） at java.util.ArrayList.get（ArrayList.java:308）在com.example.andrewberkowitz.bae.FlowerShopAdapter.getView（FlowerShopAdapter.java:106）在android.widget.AbsListView.obtainView（AbsListView.java:2780）在android.widget.ListView.measureHeightOfChildren（ListView.java:1274）在android.widget.ListView.onMeasure（ListView.java:1186）在android.view.View.measure（View.java:17594）在android.widget.RelativeLayout.measureChildHorizontal（RelativeLayout.java:719）在android.widget.RelativeLayout.onMeasure（RelativeLayout.java:455）在android.view.View.measure（View.java:17594）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5398）在android.widget.FrameLayout.onMeasure（FrameLayout.java:310）在android.view.View.measure（View.java:17594）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5398）在android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure（ActionBarOverlayLayout.java:453）在android.view.View.measure（View.java:17594）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5398）在android.widget.FrameLayout.onMeasure（FrameLayout.java:310）在android.view.View.measure（View.java:17594）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5398）在android.widget.LinearLayout.measureChildBeforeLayout（LinearLayout.java:1410）在android.widget.LinearLayout.measureVertical（LinearLayout.java:695）在android.widget.LinearLayout.onMeasure（LinearLayout.java:588）在android.view.View.measure（View.java:17594）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:5398）在android.widget.FrameLayout.onMeasure（FrameLayout.java:310）在com.android.internal.policy.impl.PhoneWindow $ DecorView.onMeasure（PhoneWindow.java:2588）在android.view.View.measure（View.java:17594）在android.view.ViewRootImpl.performMeasure（ViewRootImpl.java:2308）在android.view.ViewRootImpl.measureHierarchy（ViewRootImpl.java:1409）在android.view.ViewRootImpl.performTraversals（ViewRootImpl.java:1610）在android.view.ViewRootImpl.doTraversal（ViewRootImpl.java:1267）在android.view.ViewRootImpl $ TraversalRunnable.run（ViewRootImpl.java:6638）在android.view.Choreographer $ CallbackRecord.run（Choreographer.java:813）在android.view.Choreographer.doCallbacks（Choreographer.java:613）在android.view.Choreographer.doFrame（Choreographer.java:583）在android.view.Choreographer $ FrameDisplayEventReceiver.run（Choreographer.java:799）在android.os.Handler.handleCallback（Handler.java:733）在android.os.Handler.dispatchMessage（Handler.java:95）在android.os.Looper.loop（Looper.java:146）在android.app.ActivityThread.main（ActivityThread.java:5635） at java.lang.reflect.Method.invokeNative（Native Method）在java.lang.reflect.Method.invoke（Method.java:515）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:1291）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:1107） at dalvik.system.NativeStart.main（Native Method） 03-09 21：33：01.830 18890-19449 / com.example.andrewberkowitz.bae D / dalvikvm：GC_FOR_ALLOC释放792K，31％免费19230K / 27848K，暂停25ms，总计25ms 03-09 21：33：02.201 18890-19449 / com.example.andrewberkowitz.bae D / dalvikvm：GC_FOR_ALLOC释放83K，25％免费21018K / 27848K，暂停26ms，总计26ms 03-09 21：33：02.381 18890-19449 / com.example.andrewberkowitz.bae D / dalvikvm：GC_FOR_ALLOC释放30K，22％免费21923K / 27848K，暂停22ms，总计22ms

Answer 1

如果您导航回已经创建的活动，则不会调用onCreate。

尝试将代码移动到onResume（）：

@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();
}

每次调用OnCreate时运行一个线程

1 个答案: