图片占用太多内存

Question

Hi I have pretty simply code my images are all compressed so no one has more than 50kb. When I start my app 1 image is loaded and memory usage is around 42mb but when I scroll down to another images every other image cause memory usage to increase up to 250mb. How to fix it? Here is my code and please I am beginner so try to explain it simple.

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;


public class CustomSwip extends PagerAdapter {
private int[] imageResources = {R.drawable.j1, R.drawable.jg2,R.drawable.jg3, R.drawable.jg4, R.drawable.jg5, R.drawable.jg6, R.drawable.jg7, R.drawable.jg8, R.drawable.jg9, R.drawable.jg10, R.drawable.jg11, R.drawable.jg12, R.drawable.jg13, R.drawable.jg14, R.drawable.jg15, R.drawable.jg16};
private Context ctx;
private LayoutInflater layoutInflater;

public CustomSwip(Context c) {
    ctx = c;
}

@Override
public int getCount() {

    return imageResources.length;
}


@Override
public Object instantiateItem(ViewGroup container, int position) {
    layoutInflater = (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View itemView = layoutInflater.inflate(R.layout.activity_custom_swip, container, false);
    ImageView imageView = (ImageView) itemView.findViewById(R.id.swip_image_view);
    imageView.setImageResource(imageResources[position]);
    container.addView(itemView);
    return itemView;
}


@Override
public void destroyItem(ViewGroup container, int position, Object object) {

}


@Override
public boolean isViewFromObject(View view, Object object) {

    return (view == object);
}

}

Answer 1

Universal Image Loader is a library by nostra13 which is pretty well documented and widely used and is known for the configuration setting it provides for loading of images. In it, there is an option to load the images in RGB_565 which can decrease your memory consumption by about half (have seen the results practically) and many more.

Use .bitmapConfig(Bitmap.Config.RGB_565) in display options. Bitmaps in RGB_565 consume 2 times less memory than in ARGB_8888.

And do look into WeakReferences once. It could help in calling of Garbage Collector for memory-intensive images.

Answer 2

According to the docs for setImageResource,

This does Bitmap reading and decoding on the UI thread, which can cause a latency hiccup. If that's a concern, consider using setImageDrawable(android.graphics.drawable.Drawable) or setImageBitmap(android.graphics.Bitmap) and BitmapFactory instead.

Or simply use an image loading library to lazy load images