Android 图片加载时间

来源：互联网发布：centos ntfs 编辑：程序博客网时间：2024/06/06 23:16

图片加载时间测试：手机note3

获取图片地址

        public void loadImage() {            Intent intent = new Intent(Intent.ACTION_GET_CONTENT);            intent.setType("image/*");            startActivityForResult(intent, 1000);        }

根据Uri获取图片的绝对地址

        public String getAbsoluteImagePath(Uri uri) {            // can post image            String[] proj = { MediaStore.Images.Media.DATA };            Cursor cursor = getActivity().getContentResolver().query(uri, proj, // Which                                                                                // columns                                                                                // to                                                                                // return                    null, // WHERE clause; which rows to return (all rows)                    null, // WHERE clause selection arguments (none)                    null); // Order-by clause (ascending by name)            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);            cursor.moveToFirst();            return cursor.getString(column_index);        }

根据绝对路径活取图片文件内容：

        public byte[] readFile(String path) {            long start = System.currentTimeMillis();            File f = new File(path);            ByteArrayOutputStream bos = new ByteArrayOutputStream((int) f.length());            BufferedInputStream in = null;            try {                in = new BufferedInputStream(new FileInputStream(f));                int buf_size = 1024;                byte[] buffer = new byte[buf_size];                int len = 0;                while (-1 != (len = in.read(buffer, 0, buf_size))) {                    bos.write(buffer, 0, len);                }                long end = System.currentTimeMillis();                Log.d("PlaceholderFragment", "readFile " + path + " size=" + f.length()                        + " in time:" + (end - start) + "ms");                return bos.toByteArray();            } catch (IOException e) {                e.printStackTrace();            } finally {                try {                    in.close();                } catch (IOException e) {                    e.printStackTrace();                }                try {                    bos.close();                } catch (IOException e) {                    e.printStackTrace();                }            }            return null;        }

加载图片

        @Override        public void onActivityResult(int requestCode, int resultCode, Intent data) {            if (requestCode != 1000) {                Log.d("PlaceholderFragment", "this is not my request id!");                return;            }            if (resultCode != Activity.RESULT_OK) {                Log.d("PlaceholderFragment", "resultCode =" + resultCode);                return;            }            Uri originalUri = data.getData(); // 获得图片的uri            String imagePath = getAbsoluteImagePath(originalUri);            Log.d("PlaceholderFragment", "originalUri:" + originalUri.toString() + "  imagePath:"                    + imagePath);                                       byte[] imageData = readFile(imagePath);            Bitmap bp = null;            if (imageData != null) {                long start = System.currentTimeMillis();                Options options = new Options();                options.inSampleSize = 10;                bp = BitmapFactory.decodeByteArray(imageData, 0, imageData.length, options);                long end = System.currentTimeMillis();                Log.d("PlaceholderFragment",                        "decodeByteArray bpgetAllocationByteCount(): " + bp.getByteCount()                                + " in time:" + (end - start) + "ms");                Log.d("PlaceholderFragment",                        "currentInfo: getHeight" + bp.getHeight() + "   width:" + bp.getWidth()                                + "  getScaledHeight(1):" + bp.getScaledHeight(1)                                + "bp.getScaledHeight(2)" + bp.getScaledHeight(2));            }            if (bp != null) {                ((ImageView) getView().findViewById(R.id.iv)).setImageBitmap(bp);            }        }

运行结果：

D/PlaceholderFragment(4781): originalUri:content://media/external/images/media/54809 imagePath:/storage/emulated/0/DCIM/Camera/20150516_111556.jpg
D/PlaceholderFragment(4781): readFile /storage/emulated/0/DCIM/Camera/20150516_111556.jpg size=552204 in time:6ms
D/PlaceholderFragment(4781): decodeByteArray bpgetAllocationByteCount(): 147456 in time:22ms
D/PlaceholderFragment(4781): currentInfo: getHeight144 width:256 getScaledHeight(1):0bp.getScaledHeight(2)1

使用decodeFile加载：

        @Override        public void onActivityResult(int requestCode, int resultCode, Intent data) {            if (requestCode != 1000) {                Log.d("PlaceholderFragment", "this is not my request id!");                return;            }            if (resultCode != Activity.RESULT_OK) {                Log.d("PlaceholderFragment", "resultCode =" + resultCode);                return;            }            Uri originalUri = data.getData(); // 获得图片的uri            String imagePath = getAbsoluteImagePath(originalUri);            Log.d("PlaceholderFragment", "originalUri:" + originalUri.toString() + "  imagePath:"                    + imagePath);            long start = System.currentTimeMillis();            Options options = new Options();            options.inSampleSize = 10;            Bitmap bp = null;            bp = BitmapFactory.decodeFile(imagePath, options);            long end = System.currentTimeMillis();              Log.d("PlaceholderFragment",              "decodeByteArray bpgetAllocationByteCount(): " + bp.getByteCount()                      + " in time:" + (end - start) + "ms");            if (bp != null) {                ((ImageView) getView().findViewById(R.id.iv)).setImageBitmap(bp);            }        }

运行结果：

D/PlaceholderFragment(3130): originalUri:content://media/external/images/media/54809 imagePath:/storage/emulated/0/DCIM/Camera/20150516_111556.jpg
D/PlaceholderFragment(3130): decodeByteArray bpgetAllocationByteCount(): 147456 in time:28ms

不适用option：

        @Override        public void onActivityResult(int requestCode, int resultCode, Intent data) {            if (requestCode != 1000) {                Log.d("PlaceholderFragment", "this is not my request id!");                return;            }            if (resultCode != Activity.RESULT_OK) {                Log.d("PlaceholderFragment", "resultCode =" + resultCode);                return;            }            Uri originalUri = data.getData(); // 获得图片的uri            String imagePath = getAbsoluteImagePath(originalUri);            Log.d("PlaceholderFragment", "originalUri:" + originalUri.toString() + "  imagePath:"                    + imagePath);                       byte[] imageData = readFile(imagePath);            Bitmap bp = null;            if (imageData != null) {                long start = System.currentTimeMillis();                bp = BitmapFactory.decodeByteArray(imageData, 0, imageData.length, null);                long end = System.currentTimeMillis();                Log.d("PlaceholderFragment",                        "decodeByteArray bpgetAllocationByteCount(): " + bp.getByteCount()                                + " in time:" + (end - start) + "ms");                Log.d("PlaceholderFragment",                        "currentInfo: getHeight" + bp.getHeight() + "   width:" + bp.getWidth()                                + "  getScaledHeight(1):" + bp.getScaledHeight(1)                                + "bp.getScaledHeight(2)" + bp.getScaledHeight(2));            }            if (bp != null) {                ((ImageView) getView().findViewById(R.id.iv)).setImageBitmap(bp);            }        }

结果：

500k的图片：

D/PlaceholderFragment(15244): readFile /storage/emulated/0/DCIM/Camera/20150516_111556.jpg size=552204 in time:4ms

D/dalvikvm(15244): GC_FOR_ALLOC freed 10316K, 45% free 24585K/44212K, paused 10ms, total 10ms
D/PlaceholderFragment(15244): decodeByteArray bpgetAllocationByteCount(): 9437184 in time:57ms

3M的图片：中间的gc次数更多

D/PlaceholderFragment(15244): readFile /storage/emulated/0/DCIM/Camera/20150516_111517.jpg size=3573513 in time:42ms

D/dalvikvm(15244): GC_FOR_ALLOC freed 10316K, 45% free 24585K/44212K, paused 10ms, total 10ms

D/dalvikvm(15244): GC_FOR_ALLOC freed 1K, 22% free 27544K/34992K, paused 11ms, total 11ms

I/dalvikvm-heap(15244): Grow heap (frag case) to 35.361MB for 3573529-byte allocation
D/dalvikvm(15244): GC_FOR_ALLOC freed 3499K, 29% free 27534K/38484K, paused 9ms, total 9ms
I/dalvikvm-heap(15244): Grow heap (frag case) to 80.696MB for 51121168-byte allocation

D/PlaceholderFragment(15244): decodeByteArray bpgetAllocationByteCount(): 51121152 in time:326ms

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