Android - ImageAdapter for avoid out of memory.

ImageAdapter.java

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;


public class ImageAdapter extends BaseAdapter {
	 private Context mContext;
	 
	    // Keep all Images in array
	    public Integer[] mThumbIds = {
	            R.drawable.pic1, R.drawable.pic2,
	            R.drawable.pic3, R.drawable.pic4,
	            R.drawable.pic5, R.drawable.pic6,
	            R.drawable.pic7, R.drawable.pic8,
	            R.drawable.pic9, R.drawable.pic10,
	            R.drawable.pic11, R.drawable.pic12,
	            R.drawable.pic13, R.drawable.pic14,
	            R.drawable.pic15, R.drawable.pic16,
	            R.drawable.pic17, R.drawable.pic18,
	            R.drawable.pic19
	    };
	 
	    // Constructor
	    public ImageAdapter(Context c){
	        mContext = c;
	    }
	 
	    @Override
	    public int getCount() {
	        return mThumbIds.length;
	    }
	 
	    @Override
	    public Object getItem(int position) {
	        return mThumbIds[position];
	    }
	 
	    @Override
	    public long getItemId(int position) {
	        return 0;
	    }
	 
	    @Override
	    public View getView(int position, View convertView, ViewGroup parent) {
	        ImageView imageView = new ImageView(mContext);
//	        imageView.setImageResource(mThumbIds[position]);
	        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
	        imageView.setImageBitmap(decodeSampledBitmapFromResource(mContext.getResources(), mThumbIds[position], 100, 100));
	        imageView.setLayoutParams(new GridView.LayoutParams(70, 70));
	        return imageView;
	    }
	    
	    private Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
	            int reqWidth, int reqHeight) {

	        // First decode with inJustDecodeBounds=true to check dimensions
	        final BitmapFactory.Options options = new BitmapFactory.Options();
	        options.inJustDecodeBounds = true;
	        BitmapFactory.decodeResource(res, resId, options);

	        // Calculate inSampleSize
	        options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);

	        // Decode bitmap with inSampleSize set
	        options.inJustDecodeBounds = false;
	        return BitmapFactory.decodeResource(res, resId, options);
	    }
	    
	    private int calculateInSampleSize(
	            BitmapFactory.Options options, int reqWidth, int reqHeight) {
	    // Raw height and width of image
	    final int height = options.outHeight;
	    final int width = options.outWidth;
	    int inSampleSize = 1;

	    if (height > reqHeight || width > reqWidth) {

	        // Calculate ratios of height and width to requested height and width
	        final int heightRatio = Math.round((float) height / (float) reqHeight);
	        final int widthRatio = Math.round((float) width / (float) reqWidth);

	        // Choose the smallest ratio as inSampleSize value, this will guarantee
	        // a final image with both dimensions larger than or equal to the
	        // requested height and width.
	        inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
	    }

	    return inSampleSize;
	}
	 
}