public static int OPENGALLERYCODE = 100;
protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
    base.OnActivityResult(requestCode, resultCode, data);

    //If we are calling multiple image selection, enter into here and return photos and their filepaths.
    if (requestCode == OPENGALLERYCODE && resultCode == Result.Ok)
    {
        List<string> images = new List<string>();

        if (data != null)
        {
            //Separate all photos and get the path from them all individually.
            ClipData clipData = data.ClipData;
            if (clipData != null)
            {
                for (int i = 0; i < clipData.ItemCount; i++)
                {
                    ClipData.Item item = clipData.GetItemAt(i);
                    Android.Net.Uri uri = item.Uri;
                    var path = GetRealPathFromURI(uri);


                    if (path != null)
                    {
                        images.Add(path);
                    }
                }
            }
            else
            {
                Android.Net.Uri uri = data.Data;
                var path = GetRealPathFromURI(uri);

                if (path != null)
                {
                    images.Add(path);
                }
            }

            //Send our images to the carousel view.
            MessagingCenter.Send<App, List<string>>((App)Xamarin.Forms.Application.Current, "ImagesSelectedAndroid", images);
        }
    }
}

/// <summary>
///     Get the real path for the current image passed.
/// </summary>
public String GetRealPathFromURI(Android.Net.Uri contentURI)
{
    try
    {
        ICursor imageCursor = null;
        string fullPathToImage = "";

        imageCursor = ContentResolver.Query(contentURI, null, null, null, null);
        imageCursor.MoveToFirst();
        int idx = imageCursor.GetColumnIndex(MediaStore.Images.ImageColumns.Data);

        if (idx != -1)
        {
            fullPathToImage = imageCursor.GetString(idx);
        }
        else
        {
            ICursor cursor = null;
            var docID = DocumentsContract.GetDocumentId(contentURI);
            var id = docID.Split(':')[1];
            var whereSelect = MediaStore.Images.ImageColumns.Id + "=?";
            var projections = new string[] { MediaStore.Images.ImageColumns.Data };

            cursor = ContentResolver.Query(MediaStore.Images.Media.InternalContentUri, projections, whereSelect, new string[] { id }, null);
            if (cursor.Count == 0)
            {
                cursor = ContentResolver.Query(MediaStore.Images.Media.ExternalContentUri, projections, whereSelect, new string[] { id }, null);
            }
            var colData = cursor.GetColumnIndexOrThrow(MediaStore.Images.ImageColumns.Data);
            cursor.MoveToFirst();
            fullPathToImage = cursor.GetString(colData);
        }
        return fullPathToImage;
    }
    catch (Exception ex)
    {
        Toast.MakeText(Xamarin.Forms.Forms.Context, "Unable to get path", ToastLength.Long).Show();
    }
    return null;
}