public static void ShareVideoOnFacebook(string videoUrl, byte[] previewImage = null, string hashtag = null)
            {
                var content = new ShareVideoContent.Builder();

                content.SetPreviewPhoto(new SharePhoto.Builder().SetBitmap(BitmapFactory.DecodeByteArray(previewImage, 0, previewImage.Length)).Build());
                content.SetVideo(new ShareVideo.Builder().SetLocalUrl(Android.Net.Uri.Parse(videoUrl)).Build());
                ShareDialog.Show(UIRuntime.CurrentActivity, content.Build());
            }
        async void RequestShare(Dictionary <string, object> paramsDictionary)
        {
            if (paramsDictionary.TryGetValue("content", out object shareContent) && shareContent is FacebookShareContent)
            {
                ShareContent content = null;
                if (shareContent is FacebookShareLinkContent)
                {
                    FacebookShareLinkContent linkContent        = shareContent as FacebookShareLinkContent;
                    ShareLinkContent.Builder linkContentBuilder = new ShareLinkContent.Builder();


                    if (linkContent.Quote != null)
                    {
                        linkContentBuilder.SetQuote(linkContent.Quote);
                    }

                    if (linkContent.ContentLink != null)
                    {
                        linkContentBuilder.SetContentUrl(Android.Net.Uri.Parse(linkContent.ContentLink.AbsoluteUri));
                    }

                    if (!string.IsNullOrEmpty(linkContent.Hashtag))
                    {
                        var shareHashTagBuilder = new ShareHashtag.Builder();
                        shareHashTagBuilder.SetHashtag(linkContent.Hashtag);
                        linkContentBuilder.SetShareHashtag(shareHashTagBuilder.Build().JavaCast <ShareHashtag>());
                    }

                    if (linkContent.PeopleIds != null && linkContent.PeopleIds.Length > 0)
                    {
                        linkContentBuilder.SetPeopleIds(linkContent.PeopleIds);
                    }

                    if (!string.IsNullOrEmpty(linkContent.PlaceId))
                    {
                        linkContentBuilder.SetPlaceId(linkContent.PlaceId);
                    }

                    if (!string.IsNullOrEmpty(linkContent.Ref))
                    {
                        linkContentBuilder.SetRef(linkContent.Ref);
                    }

                    content = linkContentBuilder.Build();
                }
                else if (shareContent is FacebookSharePhotoContent)
                {
                    FacebookSharePhotoContent photoContent = shareContent as FacebookSharePhotoContent;

                    SharePhotoContent.Builder photoContentBuilder = new SharePhotoContent.Builder();

                    if (photoContent.Photos != null && photoContent.Photos.Length > 0)
                    {
                        foreach (var p in photoContent.Photos)
                        {
                            SharePhoto.Builder photoBuilder = new SharePhoto.Builder();

                            if (!string.IsNullOrEmpty(p.Caption))
                            {
                                photoBuilder.SetCaption(p.Caption);
                            }

                            if (p.ImageUrl != null && !string.IsNullOrEmpty(p.ImageUrl.AbsoluteUri))
                            {
                                photoBuilder.SetImageUrl(Android.Net.Uri.Parse(p.ImageUrl.AbsoluteUri));
                            }

                            if (p.Image != null)
                            {
                                Bitmap bmp = BitmapFactory.DecodeByteArray(p.Image, 0, p.Image.Length);

                                photoBuilder.SetBitmap(bmp);
                            }
                            photoContentBuilder.AddPhoto(photoBuilder.Build().JavaCast <SharePhoto>());
                        }
                    }

                    if (photoContent.ContentLink != null)
                    {
                        photoContentBuilder.SetContentUrl(Android.Net.Uri.Parse(photoContent.ContentLink.AbsoluteUri));
                    }

                    if (!string.IsNullOrEmpty(photoContent.Hashtag))
                    {
                        var shareHashTagBuilder = new ShareHashtag.Builder();
                        shareHashTagBuilder.SetHashtag(photoContent.Hashtag);
                        photoContentBuilder.SetShareHashtag(shareHashTagBuilder.Build().JavaCast <ShareHashtag>());
                    }

                    if (photoContent.PeopleIds != null && photoContent.PeopleIds.Length > 0)
                    {
                        photoContentBuilder.SetPeopleIds(photoContent.PeopleIds);
                    }

                    if (!string.IsNullOrEmpty(photoContent.PlaceId))
                    {
                        photoContentBuilder.SetPlaceId(photoContent.PlaceId);
                    }

                    if (!string.IsNullOrEmpty(photoContent.Ref))
                    {
                        photoContentBuilder.SetRef(photoContent.Ref);
                    }

                    content = photoContentBuilder.Build();
                }
                else if (shareContent is FacebookShareVideoContent)
                {
                    FacebookShareVideoContent videoContent        = shareContent as FacebookShareVideoContent;
                    ShareVideoContent.Builder videoContentBuilder = new ShareVideoContent.Builder();


                    if (videoContent.PreviewPhoto != null)
                    {
                        SharePhoto.Builder photoBuilder = new SharePhoto.Builder();

                        if (!string.IsNullOrEmpty(videoContent.PreviewPhoto.Caption))
                        {
                            photoBuilder.SetCaption(videoContent.PreviewPhoto.Caption);
                        }

                        if (videoContent.PreviewPhoto.ImageUrl != null && !string.IsNullOrEmpty(videoContent.PreviewPhoto.ImageUrl.AbsoluteUri))
                        {
                            photoBuilder.SetImageUrl(Android.Net.Uri.Parse(videoContent.PreviewPhoto.ImageUrl.AbsoluteUri));
                        }

                        if (videoContent.PreviewPhoto.Image != null)
                        {
                            Bitmap bmp = BitmapFactory.DecodeByteArray(videoContent.PreviewPhoto.Image, 0, videoContent.PreviewPhoto.Image.Length);

                            photoBuilder.SetBitmap(bmp);
                        }
                        videoContentBuilder.SetPreviewPhoto(photoBuilder.Build().JavaCast <SharePhoto>());
                    }

                    if (videoContent.Video != null)
                    {
                        ShareVideo.Builder videoBuilder = new ShareVideo.Builder();

                        if (videoContent.Video.LocalUrl != null)
                        {
                            videoBuilder.SetLocalUrl(Android.Net.Uri.Parse(videoContent.PreviewPhoto.ImageUrl.AbsoluteUri));
                        }

                        videoContentBuilder.SetVideo(videoBuilder.Build().JavaCast <ShareVideo>());
                    }


                    if (videoContent.ContentLink != null)
                    {
                        videoContentBuilder.SetContentUrl(Android.Net.Uri.Parse(videoContent.ContentLink.AbsoluteUri));
                    }

                    if (!string.IsNullOrEmpty(videoContent.Hashtag))
                    {
                        var shareHashTagBuilder = new ShareHashtag.Builder();
                        shareHashTagBuilder.SetHashtag(videoContent.Hashtag);
                        videoContentBuilder.SetShareHashtag(shareHashTagBuilder.Build().JavaCast <ShareHashtag>());
                    }

                    if (videoContent.PeopleIds != null && videoContent.PeopleIds.Length > 0)
                    {
                        videoContentBuilder.SetPeopleIds(videoContent.PeopleIds);
                    }

                    if (!string.IsNullOrEmpty(videoContent.PlaceId))
                    {
                        videoContentBuilder.SetPlaceId(videoContent.PlaceId);
                    }

                    if (!string.IsNullOrEmpty(videoContent.Ref))
                    {
                        videoContentBuilder.SetRef(videoContent.Ref);
                    }

                    content = videoContentBuilder.Build();
                }

                if (content != null)
                {
                    ShareApi.Share(content, shareCallback);
                }
            }
        }