Question

I let the user choose a background and the user can pick their own pictures from gallery or pictures from the list I bring with the app. I save this picture to FileOutputStream. However, my application gets really slow, I am using the following functions;

//When user picks from gallery
public void save(Bitmap bitmapImage) {
    bitmapImage = scaleBitmap(bitmapImage);

    FileOutputStream fileOutputStream = null;
    try {
        fileOutputStream = new FileOutputStream(createFile());
        bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if (fileOutputStream != null) {
                fileOutputStream.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

//When user picks from list and I load from drawables
public void save(int resId) {
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize = IMAGE_IN_SAMPLE_SIZE;
    options.inScaled = false;
    options.inJustDecodeBounds = false;

    Bitmap bitmapImage = BitmapFactory.decodeResource(context.getResources(), resId, options);

    FileOutputStream fileOutputStream = null;
    try {
        fileOutputStream = new FileOutputStream(createFile());
        bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if (fileOutputStream != null) {
                fileOutputStream.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

How can I make those functions faster?

I also get this messages:

06-15 12:02:58.884 22320-22320/com I/dalvikvm-heap: Grow heap (frag case) to 15.172MB for 2073616-byte allocation
06-15 12:03:00.716 22320-22320/com I/dalvikvm-heap: Grow heap (frag case) to 15.149MB for 2073616-byte allocation
06-15 12:03:03.129 22320-22320/com I/Choreographer: Skipped 145 frames!  The application may be doing too much work on its main thread.

Answer 1

你不应该在主线程中执行IO工作，也许你可以在一个线程中执行它，并通过hanlder更新你的ui。

  new Thread(new Runnable() {
        @Override
        public void run() {
            // save your picture
            handler.sendEmptyMessage(0);
        }
    }).start();

最好使用rxjava和rxAndroid。

希望它可以帮到你

Answer 2

如果图像太大而在另一个线程上工作也无济于事，它仍然会导致OutOfMemory，

你应该尝试使用Glide库来做你最好的方式实现它

这个链接适用于Glide \ Picasso分期付款和基本使用 -

https://inthecheesefactory.com/blog/get-to-know-glide-recommended-by-google/en

用于缩放 -

https://futurestud.io/tutorials/glide-image-resizing-scaling

Android handling big images

2 个答案: