为什么函数＆＃34; loadImageFromResouce＆＃34;当我从SQLite显示两个图像时运行22次？

Question

在下面的代码中，为什么当我从SQLite显示两个图像时，函数loadImageFromResouce会运行22次？

    public class ArrayAdapter_Product extends ArrayAdapter<Product_Object>
    {
        private TextView Ten_SP_TxtV;
        private TextView DonGia_SP_TxtV;
        private Activity context;
        private int layoutResourceId;
        private ByteArrayInputStream ImageStream;
        private Product_Object San_Pham = null;
        private Product_Holder holder;
        ArrayList<Product_Object> product = new ArrayList<Product_Object>();
        private static int reqWidth = 90;
        private static int reqHeight = 90;
        int dem = 0;
        int dem_2 = 0;
        int count_set = 0;

        public ArrayAdapter_Product(Activity context, int layoutResourceId, ArrayList<Product_Object> product) {
            super(context, layoutResourceId, product);
            this.context = context;
            this.layoutResourceId = layoutResourceId;
            this.product = product;
        }

        public View getView(int position, View view, ViewGroup parent) {
            LayoutInflater inflater = context.getLayoutInflater();
            View row = null;
            if (row == null) {
                dem++;
                row = inflater.inflate(R.layout.item_product, null, true);
                holder = new Product_Holder();
                holder.ImageV_Temp = (ImageView) row.findViewById(R.id.Anh_SP);
                ViewTreeObserver observer = holder.ImageV_Temp.getViewTreeObserver();
                observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        reqWidth = holder.ImageV_Temp.getWidth();
                        reqHeight = holder.ImageV_Temp.getHeight();
                        Log.i("BITMAP", "ReqW:" + reqWidth + ";ReqH:" + reqHeight);

                        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
                            holder.ImageV_Temp.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                        }
                        else
                            holder.ImageV_Temp.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                        }
                    }
                });
                row.setTag(holder);
                Log.d("BITMAP", "dem "+String.valueOf(dem));
            }
            else {
                holder = (Product_Holder) view.getTag();
                dem_2++;
                Log.d("BITMAP", "dem_2"+String.valueOf(dem_2));
            }
            San_Pham = product.get(position);
            byte[] Out_Image;
            Out_Image = San_Pham.Get_Image();
            ImageWorker imageWorker = new ImageWorker(holder.ImageV_Temp);
            imageWorker.execute(Out_Image);
            return row;
        }

        private class ImageWorker extends AsyncTask<byte[], Void, Bitmap> {
            private WeakReference<ImageView> WeakReference;
            public ImageWorker(ImageView imgV) {
                WeakReference = new WeakReference<ImageView>(imgV);
            }

            protected Bitmap doInBackground(byte[]... resId) {
                return loadImageFromResouce(resId[0], reqWidth, reqHeight);
            }

            protected void onPostExecute(Bitmap bitmap) {
                super.onPostExecute(bitmap);
                if (WeakReference != null && bitmap != null) {
                    ImageView imgV = WeakReference.get();

                    if (imgV != null) {
                        imgV.setImageBitmap(bitmap);
                        count_set++;
                        Log.d("BITMAP", "BYTE BITMAP SET IMAGEVIEW:" + bitmap.getByteCount());
                        Log.d("BITMAP", "SO LAN SET BITMAP:" + count_set);
                    }
                }
            }

            private Bitmap loadImageFromResouce(byte[] Out_Image, int reqWidth, int reqHeight) {
                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inJustDecodeBounds = true;
                BitmapFactory.decodeByteArray(Out_Image, 0, Out_Image.length, options);
                Log.d("BITMAP", "BYTE BITMAP BAN DAU:" + Out_Image.length);
                int insampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
                options.inJustDecodeBounds = false;
                options.inPreferredConfig = Bitmap.Config.ARGB_8888;
                options.inSampleSize = insampleSize;
                Bitmap bm = BitmapFactory.decodeByteArray(Out_Image, 0, Out_Image.length, options);
                Log.d("BITMAP", "BYTE BITMAP SAU KHI XU LY:" + bm.getByteCount());
                return bm;
            }

            private int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
                int consumeMemory = options.outWidth * options.outHeight * 4;
                String mineType = options.outMimeType;
                Log.d("BITMAP", "MEMORY: " + consumeMemory
                        + "; Ori_W: " + options.outWidth
                        + "; Ori_H: " + options.outHeight);
                Log.d("BITMAP", " " + mineType);
                final int height = options.outHeight;
                final int width = options.outWidth;
                int inSampleSize = 1;
                if (height > reqHeight || width > reqWidth) {
                    final int halfHeight = height / 2;
                    final int halfWidth = width / 2;
                    while ((halfHeight / inSampleSize) > reqHeight
                            && (halfWidth / inSampleSize) > reqWidth) {
                        inSampleSize *= 2;
                        Log.d("BITMAP", "inSampleSize - " + inSampleSize);
                    }
                }
                return inSampleSize;
            }
        }

        static class Product_Holder {
            ImageView ImageV_Temp;
        }
    }

Answer 1

要使用视图图案，您需要在视图上设置标记。这段代码：

View row = null;
if (row == null) {

没用。它应该更像是：

if (view == null) {
    // inflate the view and construct the viewholder 
    ...
} else {
   holder = (ViewHolder)view.getTag();
}

// Now operate on the view and holder