Android supports asynchronous image loading (thumbnail display) and exclusive thumbnails.

Android supports asynchronous image loading (thumbnail display) and exclusive thumbnails.

/*** Obtain the thumbnail Based on the specified image path and size * This method has two advantages: * 1. using a small memory space, the bitmap obtained for the first time is actually null, just to read the width and height. * The bitmap read for the second time is the image compressed proportionally, the third bitmap read is the desired thumbnail. * 2. The thumbnail is not stretched for the original image. Here we use the new ThumbnailUtils tool of Version 2.2, so that * images generated using this tool will not be stretched. * @ Param imagePath image path * @ param width specifies the width of the output image * @ param height specifies the height of the output image * @ return generated thumbnail */private void getImageThumbnail (ImageView thumbnails_img, string imagePath, int width, int height) {asy = new AsyncImageTask (thumbnails_img, width, height); asy.exe cute (imagePath );} /*** use an asynchronous thread to load images * thread pool */private final class AsyncImageTask extends AsyncTask <String, Integer, Bitmap> {private ImageView thumb Nails_img; private int width; private int height; public AsyncImageTask (ImageView thumbnails_img, int width, int height) {this. thumbnails_img = thumbnails_img; this. width = width; this. height = height;} protected Bitmap doInBackground (String... params) {img_bitmap = null; // memory saving options. inPreferredConfig = Bitmap. config. ARGB_4444;/* sets the decoder to be decoded in the best way */options. inPurgeable = true; options. ininputretriable = tru E; options. inJustDecodeBounds = true; // If diTher is true, the decoder will attempt to dither the decoded imageoptions. inDither = false; // do not perform image jitter processing // obtain the width and height of the image. Note that bitmap here is null img_bitmap = BitmapFactory. decodeFile (params [0], options); options. inJustDecodeBounds = false; // set it to false // calculate the zoom ratio int h = options. outHeight; int w = options. outWidth; int beWidth = w/width; int beHeight = h/height; int be = 1; if (beWidth <beHeight) {be = beWidth;} else {be = beHeight;} if (be <= 0) {be = 1;} options. inSampleSize = be; // read the image again and read the scaled bitmap. inJustDecodeBounds is set to false img_bitmap = BitmapFactory. decodeFile (params [0], options); // use ThumbnailUtils to create a thumbnail. Specify the Bitmap object to be scaled, img_bitmap = ThumbnailUtils. extractThumbnail (img_bitmap, width, height, ThumbnailUtils. OPTIONS_RECYCLE_INPUT); Return img_bitmap;} // processing result protected void onPostExecute (Bitmap result) {if (result! = Null & thumbnails_img! = Null) {thumbnails_img.setImageBitmap (result); asy_list.add (asy); asy = null; // img_bitmap.recycle (); img_bitmap = null ;}}}