内存溢出应对:把图片固定大小赋值给bitmap

主题:

//将绝对路径转换为Bitmap,动态计算inSampleSize限制图片大小此处大小为128*128 RGB_565(默认为8888)下为 2.7K
    public static Bitmap getFixedSizeImg(String filePath){
        Bitmap bitmap = null;
        BitmapFactory.Options opts = new BitmapFactory.Options();
        opts.inJustDecodeBounds = true;
        opts.inPreferredConfig = Bitmap.Config.RGB_565;
        opts.inPurgeable = true;
        opts.inInputShareable = true;
        BitmapFactory.decodeFile(filePath, opts);

        opts.inSampleSize = computeSampleSize(opts, -1, 128*128);
        opts.inJustDecodeBounds = false;

        try {
            bitmap = BitmapFactory.decodeFile(filePath, opts);
        }catch (Exception e) {
            // TODO: handle exception
        }
        return bitmap;
    }
//计算inSampleSize
    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;
    }
//计算inSampleSize
    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 the larger one when there is no overlapping zone.
            return lowerBound;
        }
        if ((maxNumOfPixels == -1) && (minSideLength == -1)) {
            return 1;
        } else if (minSideLength == -1) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }
主题结束
重写Activity此方法可查看app内存状态

@Override
public void onTrimMemory(int level) {
    super.onTrimMemory(level);
    switch (level) {
        case TRIM_MEMORY_RUNNING_MODERATE:
            LongLog.loge("你的app正在运行并且不会被列为可杀死的");
            break;
        case TRIM_MEMORY_RUNNING_LOW:
            LongLog.loge("你的app正在运行且没有被列为可杀死的");
            break;
        case TRIM_MEMORY_RUNNING_CRITICAL:
            LongLog.loge("你的app仍在运行，但是系统已经把LRU Cache中的大多数进程都已经杀死");
            break;
        case TRIM_MEMORY_BACKGROUND:
            LongLog.loge("系统正运行于低内存");
            break;
        case TRIM_MEMORY_MODERATE:
            LongLog.loge(" 系统正运行于低内存状态并且你的进程已经已经接近LRU名单的中部位置");
            break;
        case TRIM_MEMORY_COMPLETE:
            LongLog.loge("系统正运行与低内存的状态并且你的进程正处于LRU名单中最容易被杀掉的位置");
            break;
    }
}