Hi,

Today i am going to discuss about implementation of selecting multiple photos from Photo Gallery. You know, i have searched enough to find out a solution for selecting multiple images from android’s native gallery. There are 2 ways to implement multi selection of images in gallery:

1) Intent for getting multiple images
2) Define custom gallery with fetching and loading photos from native gallery.

1. Intent for getting multiple images:

As being native lover, i tried to find out a solution by implementing solution provided same like we select single image from gallery, by using below code:

Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);

But i am unable to implement a solution for selecting multiple images using the above way. Yes i came to know we can use SEND_MULTIPLE intent but i am sure how do we implement this and select mutiple images. I will try to implement it and share with you if i will get success.

2. Define custom gallery with fetching and loading photos from native gallery:

As we dont know about the Intent way solution, this is the good idea for selecting multiple photos. One of my friend Vikas Kanani is already done with this solution earlier. I did thorough testing and came to know about the below issues:

1. Images are loading very slow if we are having larger number of images, lets say 2000-5000
2. Crashing if we load more images

For resolving above issues, what i did? I have implemented Asynchronous image loading so that every image gets loaded asynchronously.

Now, lets implement improved solution

Step 1: Download Image loader library from Here.

Step 2: Add the library inside the libs folder, right click on the jar file -> Select Add to Build Path

Step 3: Define row layout for image item
row_multiphoto_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:src="@drawable/ic_launcher" />

    <CheckBox
        android:id="@+id/checkBox1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignRight="@+id/imageView1"
        android:layout_centerVertical="true"/>

</RelativeLayout>

Step 4: Define activity layout with GridView
ac_image_grid.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <GridView
        android:id="@+id/gridview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:columnWidth="100dip"
        android:gravity="center"
        android:horizontalSpacing="4dip"
        android:numColumns="auto_fit"
        android:stretchMode="columnWidth"
        android:layout_above="@+id/button1"
        android:verticalSpacing="2dip" />

    <Button
        android:id="@+id/button1"
        android:layout_alignParentBottom="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:onClick="btnChoosePhotosClick"
        android:text="Select Photos" />

</RelativeLayout>

Step 5: Define a UILApplication to declare application level configuration settings
UILApplication.java

package com.technotalkative.multiphotoselect;

import android.app.Application;

import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;

/**
 * @author Paresh Mayani (@pareshmayani)
 */
public class UILApplication extends Application {

	@Override
	public void onCreate() {
		super.onCreate();

		// This configuration tuning is custom. You can tune every option, you may tune some of them,
		// or you can create default configuration by
		//  ImageLoaderConfiguration.createDefault(this);
		// method.
		ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
			.threadPoolSize(3)
			.threadPriority(Thread.NORM_PRIORITY - 2)
			.memoryCacheSize(1500000) // 1.5 Mb
			.denyCacheImageMultipleSizesInMemory()
			.discCacheFileNameGenerator(new Md5FileNameGenerator())
			.enableLogging() // Not necessary in common
			.build();
		// Initialize ImageLoader with configuration.
		ImageLoader.getInstance().init(config);
	}
}

Step 6: Define a base activity to create a singleton instance of ImageLoader class.
BaseActivity.java

package com.technotalkative.multiphotoselect;

import android.app.Activity;

import com.nostra13.universalimageloader.core.ImageLoader;

/**
 * @author Paresh Mayani (@pareshmayani)
 */
public abstract class BaseActivity extends Activity {

	protected ImageLoader imageLoader = ImageLoader.getInstance();

}

Step 7: Now, Its time to define a main activity where we can write a logic for fetching photos from native gallery. Here i have also defined an ImageAdapter for the GridView.
MultiPhotoSelectActivity.java

package com.technotalkative.multiphotoselect;

import java.util.ArrayList;

import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.util.SparseBooleanArray;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.Toast;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.GridView;
import android.widget.ImageView;

import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.assist.SimpleImageLoadingListener;

/**
 * @author Paresh Mayani (@pareshmayani)
 */
public class MultiPhotoSelectActivity extends BaseActivity {

	private ArrayList<String> imageUrls;
	private DisplayImageOptions options;
	private ImageAdapter imageAdapter;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.ac_image_grid);

		final String[] columns = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
		final String orderBy = MediaStore.Images.Media.DATE_TAKEN;
		Cursor imagecursor = managedQuery(
				MediaStore.Images.Media.EXTERNAL_CONTENT_URI, columns, null,
				null, orderBy + " DESC");

		this.imageUrls = new ArrayList<String>();

		for (int i = 0; i < imagecursor.getCount(); i++) {
			imagecursor.moveToPosition(i);
			int dataColumnIndex = imagecursor.getColumnIndex(MediaStore.Images.Media.DATA);
			imageUrls.add(imagecursor.getString(dataColumnIndex));

			System.out.println("=====> Array path => "+imageUrls.get(i));
		}

		options = new DisplayImageOptions.Builder()
			.showStubImage(R.drawable.stub_image)
			.showImageForEmptyUri(R.drawable.image_for_empty_url)
			.cacheInMemory()
			.cacheOnDisc()
			.build();

		imageAdapter = new ImageAdapter(this, imageUrls);

		GridView gridView = (GridView) findViewById(R.id.gridview);
		gridView.setAdapter(imageAdapter);
		/*gridView.setOnItemClickListener(new OnItemClickListener() {
			@Override
			public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
				startImageGalleryActivity(position);
			}
		});*/
	}

	@Override
	protected void onStop() {
		imageLoader.stop();
		super.onStop();
	}

	public void btnChoosePhotosClick(View v){

		ArrayList<String> selectedItems = imageAdapter.getCheckedItems();
		Toast.makeText(MultiPhotoSelectActivity.this, "Total photos selected: "+selectedItems.size(), Toast.LENGTH_SHORT).show();
		Log.d(MultiPhotoSelectActivity.class.getSimpleName(), "Selected Items: " + selectedItems.toString());
	}

	/*private void startImageGalleryActivity(int position) {
		Intent intent = new Intent(this, ImagePagerActivity.class);
		intent.putExtra(Extra.IMAGES, imageUrls);
		intent.putExtra(Extra.IMAGE_POSITION, position);
		startActivity(intent);
	}*/

	public class ImageAdapter extends BaseAdapter {

		ArrayList<String> mList;
		LayoutInflater mInflater;
		Context mContext;
		SparseBooleanArray mSparseBooleanArray;

		public ImageAdapter(Context context, ArrayList<String> imageList) {
			// TODO Auto-generated constructor stub
			mContext = context;
			mInflater = LayoutInflater.from(mContext);
			mSparseBooleanArray = new SparseBooleanArray();
			mList = new ArrayList<String>();
			this.mList = imageList;

		}

		public ArrayList<String> getCheckedItems() {
			ArrayList<String> mTempArry = new ArrayList<String>();

			for(int i=0;i<mList.size();i++) {
				if(mSparseBooleanArray.get(i)) {
					mTempArry.add(mList.get(i));
				}
			}

			return mTempArry;
		}

		@Override
		public int getCount() {
			return imageUrls.size();
		}

		@Override
		public Object getItem(int position) {
			return null;
		}

		@Override
		public long getItemId(int position) {
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {

			if(convertView == null) {
				convertView = mInflater.inflate(R.layout.row_multiphoto_item, null);
			}

			CheckBox mCheckBox = (CheckBox) convertView.findViewById(R.id.checkBox1);
			final ImageView imageView = (ImageView) convertView.findViewById(R.id.imageView1);

			imageLoader.displayImage("file://"+imageUrls.get(position), imageView, options, new SimpleImageLoadingListener() {
				@Override
				public void onLoadingComplete(Bitmap loadedImage) {
					Animation anim = AnimationUtils.loadAnimation(MultiPhotoSelectActivity.this, R.anim.fade_in);
					imageView.setAnimation(anim);
					anim.start();
				}
			});

			mCheckBox.setTag(position);
			mCheckBox.setChecked(mSparseBooleanArray.get(position));
			mCheckBox.setOnCheckedChangeListener(mCheckedChangeListener);

			return convertView;
		}

		OnCheckedChangeListener mCheckedChangeListener = new OnCheckedChangeListener() {

			@Override
			public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
				// TODO Auto-generated method stub
				mSparseBooleanArray.put((Integer) buttonView.getTag(), isChecked);
			}
		};
	}

}

Download this example from here: Android – Select multiple photos from Gallery

Reference: Universal Image Loader