手持机项目里集体卡PagerAdapter显示滑动多张人员头像照片,滑动预览时崩溃。OOM内存溢出。转载帖子:很多照片是好几MB一张,因为目前的Android系统对运行的程序都有一定的内存限制,一般是16MB或24MB(视平台而定),不做处理直接加载的话必然会报OOM (Out Of Memmory)。网上有很多解决android加载bitmap内存溢出的方法,下面是我转载出来的代码:
** * * Solve the problem of OutOfMemoryError ,by loading multiple large graphs(large Bitmap) in Android. * Bitmap bitmap = BitmapFactory.decodeByteArray(Util.decodeBitmap(imagePath), 0, Util.decodeBitmap(imagePath).length); */ public static byte[] decodeBitmap(String path) { BitmapFactory.Options opts = new BitmapFactory.Options(); opts.inJustDecodeBounds = true;// 设置成了true,不占用内存,只获取bitmap宽高 BitmapFactory.decodeFile(path, opts); opts.inSampleSize = computeSampleSize(opts, -1, 1024 * 800); opts.inJustDecodeBounds = false;// 这里一定要将其设置回false,因为之前我们将其设置成了true opts.inPurgeable = true; opts.inInputShareable = true; opts.inDither = false; opts.inPurgeable = true; opts.inTempStorage = new byte[16 * 1024]; FileInputStream is = null; Bitmap bmp = null; ByteArrayOutputStream baos = null; try { is = new FileInputStream(path); bmp = BitmapFactory.decodeFileDescriptor(is.getFD(), null, opts); double scale = getScaling(opts.outWidth * opts.outHeight, 1024 * 600); Bitmap bmp2 = Bitmap.createScaledBitmap(bmp, (int) (opts.outWidth * scale), (int) (opts.outHeight * scale), true); bmp.recycle(); baos = new ByteArrayOutputStream(); bmp2.compress(Bitmap.CompressFormat.JPEG, 100, baos); bmp2.recycle(); return baos.toByteArray(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); baos.close(); } catch (IOException e) { e.printStackTrace(); } System.gc(); } return baos.toByteArray(); } private static double getScaling(int src, int des) { /** * 48 目标尺寸÷原尺寸 sqrt开方,得出宽高百分比 49 */ double scale = Math.sqrt((double) des / (double) src); return scale; } public static int computeSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) { int initialSize = computeInitialSampleSize(options, minSideLength, maxNumOfPixels); int roundedSize; if (initialSize <= 8) { roundedSize = 1; while (roundedSize < initialSize) { roundedSize <<= 1; } } else { roundedSize = (initialSize + 7) / 8 * 8; } return roundedSize; } private static int computeInitialSampleSize(BitmapFactory.Options options, int minSideLength, int maxNumOfPixels) { double w = options.outWidth; double h = options.outHeight; int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math .sqrt(w * h / maxNumOfPixels)); int upperBound = (minSideLength == -1) ? 128 : (int) Math.min( Math.floor(w / minSideLength), Math.floor(h / minSideLength)); if (upperBound < lowerBound) { return lowerBound; } if ((maxNumOfPixels == -1) && (minSideLength == -1)) { return 1; } else if (minSideLength == -1) { return lowerBound; } else { return upperBound; } }