Xamarin无法访问已处置的对象。\ n对象名称：＆＃39; System.Net.Sockets.NetworkStream从库向服务器发送照片时

Question

我有一个无法访问已处置的对象。\ n对象名称：＆＃39; System.Net.Sockets.NetworkStream异常在我尝试将图片从库发送到我的服务器时抛出。

出于贬值的目的，我制作了两种方法，其中一种方法有效，一种方法无效。工作的那个使用一个虚拟字节数组，并且不使用图片Stream对象并从中生成一个字节数组。我将这两种方法都挂钩到OnImagePickerFinishedPickingMedia。

所以我们在共享PCL代码的屏幕上有一个按钮，点击

await DependencyService.Get<IPicturePicker>().GetImageStreamAsync();

仅仅为了调试pruposes我使所有代码都在一个地方发生，因此更容易跟踪错误。在GetImageStreamAsync（）

中

        public Task<byte[]> GetImageStreamAsync()
        {
            // Create and define UIImagePickerController
            imagePicker = new UIImagePickerController
            {
                SourceType = UIImagePickerControllerSourceType.PhotoLibrary,
                MediaTypes = UIImagePickerController.AvailableMediaTypes(UIImagePickerControllerSourceType.PhotoLibrary)
            };

            // Set event handlers
            imagePicker.FinishedPickingMedia += OnImagePickerFinishedPickingMedia;
            imagePicker.Canceled += OnImagePickerCancelled;

            // Present UIImagePickerController;
            UIWindow window = UIApplication.SharedApplication.KeyWindow;
            var viewController = window.RootViewController;
            viewController.PresentModalViewController(imagePicker, true);

            // Return Task object
            taskCompletionSource = new TaskCompletionSource<byte[]>();
            return taskCompletionSource.Task;
        }

这两个方法的部分相同，并且是一些Xamarin示例的完整副本。

现在这里是一个工作方法，并将数组写入db而没有任何问题：

        void OnImagePickerFinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs args)
        {
            UIImage image = args.EditedImage ?? args.OriginalImage;

            if (image != null)
            {
                // Convert UIImage to .NET Stream object
                NSData data = image.AsJPEG(1);
                Stream stream = data.AsStream();
                var arrayData = data.ToArray();

            try
            {

                CallMe();

            }
            catch (Exception e)
            {
                Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Repository Error 3",
                Errors.RepositoryError_3 + Environment.NewLine + e.ToString(), "Ok");
            }


            taskCompletionSource.SetResult(arrayData);
            }
            else
            {
                taskCompletionSource.SetResult(null);
            }
            imagePicker.DismissModalViewController(true);
        }

        private async void CallMe()
        {
            try
            {
                string xq = "csdcsdc";
                byte[] byteArray = Encoding.UTF8.GetBytes(xq);
                var gal = new GalleryResource()
                {
                    Pic = byteArray
                };

                var c = RepositoryService.ConvertObjectToStringContentStatic(gal);
                var client = new HttpClient();
                var response = await client.PostAsync(Settings.EndPoint + "api/gallery/", c);

            }
            catch (Exception e)
            {
                Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Call me!!!",
                Errors.RepositoryError_3 + Environment.NewLine + e.ToString(), "Ok");
            }

        }

以下是FAILS：

        private async void CallMe()
        {
            try
            {
                string xq = "csdcsdc";
                byte[] byteArray = Encoding.UTF8.GetBytes(xq);
                var gal = new GalleryResource()
                {
                    Pic = byteArray
                };

                var c = RepositoryService.ConvertObjectToStringContentStatic(gal);
                var client = new HttpClient();
                var response = await client.PostAsync(Settings.EndPoint + "api/gallery/", c);

            }
            catch (Exception e)
            {
                Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Call me!!!",
                Errors.RepositoryError_3 + Environment.NewLine + e.ToString(), "Ok");
            }

        }


        void OnImagePickerFinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs args)
        {
            UIImage image = args.EditedImage ?? args.OriginalImage;

            if (image != null)
            {
                // Convert UIImage to .NET Stream object
                NSData data = image.AsJPEG(1);
                Stream stream = data.AsStream();
                var arrayData = data.ToArray();

            try
            {

                CallMe(arrayData);

            }
            catch (Exception e)
            {
                Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Repository Error 3",
                Errors.RepositoryError_3 + Environment.NewLine + e.ToString(), "Ok");
            }


            taskCompletionSource.SetResult(arrayData);
            }
            else
            {
                taskCompletionSource.SetResult(null);
            }
            imagePicker.DismissModalViewController(true);
        }

        private async void CallMe(byte[] byteArray)
        {
            try
            {
                string xq = "csdcsdc";
                //byte[] byteArray = Encoding.UTF8.GetBytes(xq);
                var gal = new GalleryResource()
                {
                    Pic = byteArray
                };

                var c = RepositoryService.ConvertObjectToStringContentStatic(gal);
                var client = new HttpClient();
                var response = await client.PostAsync(Settings.EndPoint + "api/gallery/", c);

            }
            catch (Exception e)
            {
                Xamarin.Forms.Application.Current.MainPage.DisplayAlert("Call me!!!",
                Errors.RepositoryError_3 + Environment.NewLine + e.ToString(), "Ok");
            }

        }

如果有人有任何关于为什么会在第二位弹出异常的想法，我会非常感激。到目前为止，我已尝试过多种方法来执行此代码，但尚未找到解决方案。感谢。